Clydesdale(Model 8491)

Non-Catalytic,
Wood Burning
Fireplace Insert

OWNER'S MANUALINSTALLATION & OPERATING
INSTRUCTIONS

Please read this entire owner’s manual before you install and use your new Clydesdale woodburning fireplace insert. To reduce the risk of fire, follow the installation instructions. Failure
to follow these instructions may result in property damage, bodily injury, or even death.

SAVE THESE INSTRUCTIONS FOR FUTURE REFERENCE!

Contact Local Authorities Having Jurisdiction (Building Department or Fire Officials)
About Permits, Restrictions, and Installation Inspection Required in Your Area.

Hearthstone Quality Home Heating Products, Inc. ®
Clydesdale Model 8491
Manual: 6400-40462
R: 3 - 5/31/2011

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Clydesdale Fireplace Insert Model 8491

Intentionally Blank

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Table of Contents
INTRODUCTION .......................................................................................................................................................... 4
CODES ...................................................................................................................................................................... 4
SAFETY INFORMATION ............................................................................................................................................... 5PERIODIC CHECKLIST ................................................................................................................................................ 6
EMERGENCY PROCEDURES ........................................................................................................................................ 6
SPECIFICATIONS ........................................................................................................................................................ 7
INSTALLATION ........................................................................................................................................................... 8
Unpacking ...................................................................................................................................................................... 8
Packing List.................................................................................................................................................................... 8
Hearth Requirements & Floor Protection ....................................................................................................................... 9
Clearances to NFPA 211 Protected Surfaces ................................................................................................................ 9
Clearance to combustibles............................................................................................................................................. 9
Installing the Insert ....................................................................................................................................................... 10
Installing the surround.................................................................................................................................................. 14
Removing & Reversing the Door.................................................................................................................................. 14
Removing the Ash Lip Cover & Façade ....................................................................................................................... 15
Blower Power Cord Routing......................................................................................................................................... 16

VENTING COMPONENTS & CONFIGURATION .............................................................................................................. 17
Installing a Venting System.......................................................................................................................................... 17
Connecting Your Wood Fireplace Insert ...................................................................................................................... 17
Connecting to a Prefabricated Metal Chimney............................................................................................................. 17
Connection to a Masonry Chimney .............................................................................................................................. 18

OPERATION ............................................................................................................................................................. 21
Controls & Features ..................................................................................................................................................... 21
Operating the Blower ................................................................................................................................................... 21
Choosing Firewood ...................................................................................................................................................... 21
Wood Heat Value: Sorted By Btu Content ................................................................................................................... 22
Building a Fire .............................................................................................................................................................. 23
Breaking in Your Wood Fireplace Insert....................................................................................................................... 23
Operating Your Insert Efficiently .................................................................................................................................. 24
Intermittent Operation .................................................................................................................................................. 25
Building a Fire for Everyday Use.................................................................................................................................. 25
Disposal of Ashes ........................................................................................................................................................ 25
Over-Fire Caution......................................................................................................................................................... 25

MAINTENANCE ......................................................................................................................................................... 26
Creosote Formation and Need for Removal................................................................................................................. 26
Gaskets........................................................................................................................................................................ 26
Glass............................................................................................................................................................................ 26
Cast Iron ...................................................................................................................................................................... 27
Blower System ............................................................................................................................................................. 28

TROUBLESHOOTING ................................................................................................................................................. 29
Basic Heating Issues.................................................................................................................................................... 29
Draft Sampling Access Port ......................................................................................................................................... 29
Troubleshooting Guide................................................................................................................................................. 30

REPLACEMENT PARTS & OPTIONAL ACCESSORIES ................................................................................................... 31
SAFETY LABEL ........................................................................................................................................................ 32

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Introduction
Congratulations! You have just invested in a mostunique wood burning Fireplace Insert – theClydesdale Model 8491 is a clean burning EPA
certified, non-catalytic wood burning Fireplace
Insert. You can be proud to join the Hearthstonefamily with our Premier Cast Iron Wood Burning
Fireplace Insert. The generous firebox depth andwidth allows for loading of wood up to 22 inches
long!
Your purchase ensures years of clean, comfortable
heat with minimal maintenance. You will receive thebenefits of the most advanced technology in woodburning without the cost and maintenancerequirements of a catalytic Fireplace Insert. The
Clydesdale blends modern technology with theunique beauty and heating qualities of soapstone(used as the firebox lining) and cast iron. Soapstone
is well known for its even heat production and longheat-retaining ability. We trust that you willappreciate the quality of our handcrafted product.
Please read this manual in its entirety. Its purpose
is to familiarize you with your Fireplace Insert's safe
installation, proper break-in, operation andmaintenance. It contains information that is useful to
you now, and in the years to come. So keep it handy
and refer to it as needed.
Use these instructions as well as national, state, andlocal building codes to install your Fireplace Insert.
Ensure to maintain the designated stovepipe andFireplace Insert clearances to walls, ceilings, hearth,and other combustible surfaces. This will help

reduce the risk of fire. Failure to follow these
instructions can result in property damage, bodily
injury, and even death.
Keep furniture, drapes, curtains, wood, paper, andother combustibles far away from the Fireplace
Insert. Never install the Fireplace Insert in a location
where gasoline, kerosene, charcoal lighter fluid orother flammable liquids are used or stored.
SAFETY NOTICE:A HOUSE FIRE MAY RESULT IF THIS FIREPLACE
INSERT IS NOT INSTALLED PROPERLY. FOR YOUR
SAFETY, CAREFULLY FOLLOW THE INSTALLATIONINSTRUCTIONS. CONTACT LOCAL BUILDING OR
FIRE OFFICIALS ABOUT RESTRICTIONS AND
INSTALLATION INSPECTION IN YOUR AREA.

The performance of your Fireplace Insert depends
on many variables.
Since all installations are
unique, the general information and operatingprocedures presented here can only serve as useful
guidelines rather than hard and fast rules. Should
you have any questions, do not hesitate to contact
your dealer for additional information.
This Fireplace Insert is manufactured and warrantedby:Hearthstone Quality Home Heating Products, Inc®
317 Stafford Ave.
Morrisville, VT. 05661
www.hearthstonestoves.com

Codes
When you install your Clydesdale wood Fireplace
Insert, it is imperative that you adhere to all local
codes, which can be obtained from either of thefollowing two National sources:

National Fire Protection Association, Inc.
(NFPA)
Battery March Park
Quincy, MA 02269
http://www.nfpa.org

American National Standards Institute, Inc.
(ANSI)
1430 Broadway
New York, NY 10018
www.ansi.org

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Safety Information
Read and understand this Owner's Manual
thoroughly before installing and using thisFireplace Insert.

fire starters to start or invigorate the fire. These
fuels can possibly generate carbon monoxide,
which can sap the supply of oxygen. Keep allsuch materials away from the Fireplace Insert.

Make sure to install your Fireplace Insert:
According to the manufacturer's
recommendations.

Never use a log grate or other device to elevate
the fire.

In accordance with all applicable codes.
With the proper sized chimney.
When using your Fireplace Insert:
Warn children and others unfamiliar withwoodstoves of the danger of touching hot,radiating surfaces of your Fireplace Insert. For
your additional safety, obtain hearth and stove
guards through your local dealer.
Follow recommended break-in procedure as
outlined in this manual.
Burn natural wood only. Higher efficiencies andlower emissions result when burning air-dried,seasoned wood, as compared to green or
freshly cut wood.
Use caution when loading firewood into a hot
stove.
Inspect the stovepipe, chimney connector andchimney, as recommended.

Follow these safety precautions:
Never modify this Fireplace Insert in any way,especially the primary air control system.
Never burn kiln dried wood, painted or treatedwood, solvents, trash, plywood, colored or
glossy paper, plastic, artificial logs, cardboard,coal, or driftwood. Especially, do not burncoal in this Fireplace Insert.
Never use gasoline type fuel, kerosene,
charcoal lighter fluid, or other liquid fuels or solid

Do Not allow logs to rest against or otherwise
come in contact with the glass when the door isclosed.
Do Not slam the door or use the door to force
wood in to the Fireplace Insert.
Never over-fire your Fireplace Insert
Never put articles of clothing or candles on a hot
Fireplace Insert.
Do Not connect the Fireplace Insert to a fluethat is serving another appliance.
Other safety guidelines
As a general rule, keep all combustible items
such as furniture, drapes, clothing, and otheritems, at least 36" (0.92 m) from the Fireplace
InsertInstall a smoke detector, preferably in an area
away from your wood Fireplace Insert.
Install a CO detector as a rule. Wood burning
appliances can generate little CO, but oil andgas burning appliances can produce hugeamounts if not operating properly.
Keep a fire extinguisher handy. We recommend
the type rated "A B C."
Dispose of ashes properly.
Keep children and pets away from the stove;
they could be burned by touching a hot stove.
Clean your chimney system as needed.

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Periodic Checklist
Perform each of these tasks at the specified
intervals.
At the End of Every Week:
Empty ashes from the firebox (sooner if thefirebox begins to fill up).
At the Beginning of Every Other Month:
A visual inspection of the flue liner or chimney
for creosote is recommended depending upon
your use of the stove.
Check door seals using the "dollar bill test." When the fire is out and the insert is cool, shutthe door on a dollar bill. If the bill pulls out
without any resistance, then your insert’s door
isn't sealed properly. To tighten the seal, adjust
the latch spring tension or change the door
gasket if necessary.

At the End of Every Season:
Clean any chimney connector thoroughly.
Replace any pieces that show signs of rust or
deterioration.
Inspect and, if necessary, clean your chimney(flue liner).
Thoroughly clean out the firebox of the Fireplace
Insert.
Inspect all door gasket material and replace ifworn, frayed, cracked or extremely hard.
Replace any badly cracked refractory soapstone
in the firebox.
Clean dust away from the ash lip assembly andgrills.
Remove the Ash Lip Cover and inspect theblower assembly - clean if necessary.

Emergency Procedures
If you have a stovepipe or chimney fire, follow these
instructions:
1. If the fire is too threatening, leave the area andcall the fire department immediately! If not,perform the next two steps.
2. Close the primary air control.
3. Keep the Fireplace Insert door closed!
WARNING: DO NOT ATTEMPT TO PUT OUT ASTOVEPIPE OR CHIMNEY FIRE BY THROWINGWATER ONTO THE STOVE, STOVEPIPE, OR
CHIMNEY.
THE
EXTREMELYHIGH
TEMPERATURE ASSOCIATED WITH SUCH FIRESCAN CAUSE INSTANTANEOUS STEAM AND
SERIOUS BODILY HARM.

Once the chimney fire has expired, leave the primary
air control closed and let the fire in the Fireplace
Insert die out completely.
DO NOT burn theFireplace Insert again until the Fireplace Insert,
connector pipe, liner, and chimney are all thoroughly
inspected for any sign of damage. You must correct
any damage before using your Fireplace Insert
again.
To remove the Clydesdale for inspection purposes,
disconnect the venting from inside the firebox.
Carefully remove the surround from the insert, andslide the insert away from the fireplace.

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Specifications
Maximum Heat Output: 60,000 BTU per hour of
cordwood (based on independent laboratory test
results).
Size of Heated Area:

Depth:

24.63” (62.56 cm)

Front Door Size:

22" wide x 11.5" high(55.88 x 29.21 cm)

Stovepipe Size:

6" (152 mm) diameter

Metal Chimney:6" (152 mm) inside diameter

Masonry Chimney:6” (15.2cm) inside diameter(round flue)
8” x 8” (20 x 20cm) (square
flue)

Flue Exit:

Top exit only

Actual Weight:

550 pounds

Castings Finish:

Painted Matte; and Porcelain
EnamelUp to 2,000 square feet.

Firebox Capacity: 2.4 cubic feet or 48 pounds ofwood (The amount and weight of wood contained per
cubic foot of firebox volume can vary from 15 to 36
lbs. per cubic foot depending on type of wood,
moisture content, packing density and other factors.
As a constant for comparison and test purposes, weare assuming 20 lbs. of seasoned hardwood per
cubic foot of firebox volume).
Maximum Log Length: 22” (55.88 cm)
Height:23.12" (58.72 cm)

Width:

31.62” (80.31 cm)

Figure 1 – Clydesdale Dimensions

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Installation
UnpackingHearthstone packages your Clydesdale Fireplace
Insert with the greatest care so that it ships safely.
Under certain circumstances, however, damage canstill occur during transit and handling. When you
receive your Fireplace Insert, unpack it carefully,
inspecting it, and all parts for damage. Also, ensurethat all parts are included. If any parts are damaged
or missing, please contact your dealer immediately.

Packing List
1- Clydesdale 8491 Fireplace Insert
1- Façade and Ash Lip w/ blower (in place on insert)
1- Façade Top Grill (in place on insert)
1- Surround Kit Box (ships on top of insert)
In Firebox:
1- Box, Refractory Stone Kit
1- Bag, Door Handle Kit
1- Envelope, Owner’s Manual Packet
1- Pouch, Touch-up Paint (Enamel only)

Pre-Installation Prep

fireplace prior to installing the insert (see illustration
on page 18).
WITH ALL CHIMNEYS, A POSITIVE CONNECTION
MUST BE MADE BETWEEN THE FIREPLACE
INSERT’S FLUE COLLAR AND THE CHIMNEY (seepage 17).

Ensure that the Fireplace Insert will have enoughclearance to combustible materials in the vicinity.
These combustibles can include walls, floor, ceiling,
fireplace mantle, and chimney decor. You must
carefully consider the clearances to all of these
combustibles before actually connecting yourFireplace Insert.
Read this chapter to obtain a sound understandingof how to properly install your Fireplace Insert.
Contact the following agency for more information:
National Fire Protection Agency
Batterymarch Park
Quincy, MA 02269
1-800-344-3555
1-617-770-3000
www.nfpa.org

When installing this unit in a fireplace, you must
attach the provided metal label (3300-625) to the

Figure 2 – Minimum Fireplace Dimensions

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Hearth Requirements & Floor
Protection
Combustible flooring must be protected with acovering of noncombustible material (slate, marble
tiles, other noncombustible material can be used forthis purpose). The floor protection must extend
beyond the body of the Fireplace Insert at theminimum as follows and have a minimum “R-Value”
of 1.0.

1. Use either the K-factor or the C-factor formula
explained above to convert specifications not
expressed as R-values.
2. For multiple layers of floor protectors, simply add
the R-values of each layer to determine theoverall R-value of the layers.
If the overall R-value of your setup is greater than the
R-value of the specified floor protector, then yoursetup is acceptable.

Clearances to NFPA 211 Protected
Surfaces
You can reduce the clearances to combustible
surfaces by using any National Fire Protection
Agency (NFPA) approved wall protection system.
Refer to NFPA 211 for specific and complete details:
National Fire Protection Agency
Battery March Park
Quincy, MA 02269
1-800-344-3555
1-617-770-3000
www.nfpa.org

Figure 3 – Hearth Requirements
Noncombustible Material
Gypsum or plaster board

Thickness
1

Wallboard, Wonderboard, or1
DurockCeramic board (Fiberfrax or
1
Micor)
Nominal solid clay brick1
1

Ceramic wall or floor tile
Mineral wool insulation
Cement mortar

2

Horizontal still air *22

R-value

1

/2 

1

/2 

1

/2 

1.10

1

0.20

1

/4 

0.01

1

3.12

1

0.20

1

0.92

/8 

Clearance to combustibles

0.45
0.20

Floor protectors come with various types of
specifications. To convert a floor protector’s
specification to an R-value, do one of the following:
1. If the R-value is given, use that value - noconversion is needed.
2. If a K-factor is given with a required thickness (T)in inches, use this formula: R-value = 1/K x T
3. If a C-factor is given, use the formula: R-value =1/C

Figure 4 – clearances to combustibles
A- Side wall
B- Mantle and top trim
B- Mantle/ with mantle shield kit
C- Trim= 12”= 27” *
= 11” *
= 9”

* Measured from top of sheet metal shroud

To determine the R-value of the proposed alternate
floor protector:
1
2

According to Intertek Testing Services, Inc.
According to ASHRAE Handbook of Fundamentals 1977

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Clydesdale Fireplace Insert Model 8491

Installing the Insert
Step One: Remove the contents of the firebox. This
will include the owner’s manual packet, a box ofsoapstone refractory bricks, the handle knob
assembly, and a pouch containing enamel touch-up(if applicable).
Step Two: Remove the Clydesdale from the pallet(see Photo 1).
Locate the three mounting clips attached to theleveling bolts (two in the front and one in the back)that secure the insert to the shipping pallet.
1. Using a 1/2” wrench, remove the rear lag
screw and mounting clip.
2. Check the front clips – if there is sufficient
clearance above the lag screws to clear thefacade, remove them.
3. Otherwise, if the lag screw is close to andunder the façade (see photo 1), carefullyloosen the front clip lag screws about one
turn. Take care to not damage the finish on
the façade.
4. Slide the insert backwards about one inch todisengage the front clips.
The Insert ships with the Façade and ash lip coverinstalled. You should not need to remove these in a
typical installation.

Photo 2 – Door Handle & Latch Detail (Façade
removed)Step Four: Measure the opening of the fireplace.
When measuring the fireplace cavity, you will need todetermine the following:
1. Will the flue collar be installed in the forward
or aft position? The depth of the firebox will
determine the location of the flue collar.
NOTE: the collar is installed at the factory in
the aft position to accommodate the mostcommon type of install that requires use ofan elbow or flex connector for attachment tothe chimney liner. To change the collar to
the forward position for a shallow fireplace,follow the instructions in step five. Proceed
to the next step if the aft position is correct
for your installation.

Photo 1 – Pallet Mounting Clip Detail (Right Front
Shown - Façade Installed)

Step Three: Install the wooden knob onto the latch
handle. The knob, bolt, and washer are located in aplastic bag removed from the firebox in step one.
Place the washer onto the bolt and then push the bolt
through the knob. Turn the bolt onto the latch handle
and tighten with a hex wrench. Handle is shown
installed correctly in photo 2.

Figure 5 – Flue Collar Detail
2. Note: With the collar is in the aft position - toproperly attach the liner or connector to the

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flue collar using all three screws, you must
remove the baffle/plenum and drop the flue
collar into the firebox for attachment of theflue liner. If the baffle/plenum and flue collar
do not need to be removed, you can skip to
step 7.
Step Five: Change the position of the flue collar ifnecessary. To remove the flue collar, reach inthrough the flue collar and locate the four bolts
threaded down through the insert top on the cornersof the flue collar. Remove the nuts with a 7/16”
wrench. Lower, and turn the collar 180 degrees tothe forward position. Fit the four holes on the collar
over the four bolts. Fasten the nuts back onto thebolts and tighten them with the 7/16” wrench. Now
place the insert into the fireplace opening andconnect to the flue liner (meeting UL 1777).

Draft SamplingPort

Photo 5 - Collar in Default 30º Aft Position (airshroud removed for clarity)

Photo 3 – Collar Mounting Detail (Inside Firebox)

Photo 6 – Collar in Forward (90º Position)
NOTE: In order to connect the liner to the flue
collar properly with three screws when the flue
collar is in the aft (default) position, you must
remove the baffle/plenum and drop the collar into
the firebox. Removing the baffle will also allow
you to connect the flue liner to the flue collar in
the forward position if space above the insert
installed in the fireplace is limited.
Photo 4 – Air Shroud Installed (default)

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Step Six: Remove the baffle/plenum.

into the fireplace opening. Drop the flue liner(meeting UL 1777) into the firebox through theflue collar opening. Attach the flue liner, orconnector to the collar, push the collar and flueliner up to the top of the firebox, ensure the collar
slips onto the four bolts, and secure it by turning
the nuts back onto the bolts and tighten with a
7/16” wrench.
Place the baffle / secondary air assembly back into
the firebox and re-install.

Stone Clips.

Photo 7 – Stone Clip Detail
NOTE: Before the baffle can be removed, the 3stone retaining clips (one in the rear and one oneach side) must be removed from the firebox.
Remove the clips by removing the fasteners that
hold them to the firebox.
1. To remove the baffle / secondary air plenum,
loosen the two socket head machine screws that
hold it in place with a 5/32” hex wrench (seephoto below). Once these screws are loose, lift
the baffle assembly off the screws and maneuver
it carefully out of the firebox.

CAUTION: THE BAFFLE MATERIAL IS A HIGHTEMPERATURE CERAMIC. IT WILL LAST FOR
MANY YEARS UNDER NORMAL USE; HOWEVER,
IT IS EASILY DAMAGED BY IMPACT OR FORCE.
APPLY PRESSURE TO THE STAINLESS STEELAIR TUBES AND CAST IRON ONLY!

a. Place the baffle inside the stove with the ceramicboard facing up, and the stainless steel shelf tabs
forward.
b. Lift the baffle and slide the rear baffle sleeves
fully into the slots on the rear of the unit. The
slots on the baffle will drop back onto thethreaded rods in the back of the fireboxc. Gently lower the front of the baffle until the shelftabs are resting on the sidewall.
d. To verify that the baffle is in the correct position,
gently tug down on the front of the baffle. If it
does not move – placement is correct. Tighten
the machine screws loosened in step one.
Ceramic Baffle

Photo 8 – Plenum Fastener Detail
The removable plenum/baffle assembly inside the
Clydesdale firebox.
(Shown looking straight into thefirebox.)

NOTE: If access to the top of the insert isrestricted when installed, you will want to loosely
attach the mounting bracket for the surroundnow. For installation details see the instructions
provided with the surround.

Shelf Tab

Photo 9 – Baffle/Plenum Shelf Tab Detail

2. With the baffle/plenum out of the firebox, remove
the flue collar as described in step five. Place theflue collar in the firebox and insert the Clydesdale

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Step Seven: With the unit in the desired position
within the fireplace, level the unit using a box end
wrench on the square portion of the left and rightleveling bolts (if façade is installed). Use a 9/16”
socket wrench on the Stover nut to adjust the rearleveling bolt (see photos 10 through 12).

Step Eight: Install the soapstone refractory pieces in
the firebox (see photos 13 through 15).
The Clydesdale refractory stone set includes thefollowing stones:
9 ea: 4-1/2” x 9” (A)
1 ea: 4-1/2” X 4-1/2” (B)
2 ea: 4-1/2” X 12” Angled Cut (C)2 ea: 4-1/2” x 11-1/4” Angled Cut (D)

A

A

A

A

A
A

B

Photo 10 – Leveling Bolt Detail (Right Front Shown
with Façade removed & Stover lock nut installed)

Photo 13 – Firebox Floor Stones

A

Photo 11 – Rear Leveling Bolt Detail (With Stoverlock nut installed - accessed in Firebox)

A

A

Photo 14 – Install & Secure Firebox Rear Stones

CD

Photo 15 – Left and Right Side Stones

Photo 12 – Rear Leveling Bolt (Rear View)

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Installing the surround3.

Remove, and set aside the two hinge pins and any
spacer washers.

Step Nine: Remove the surround components fromthe large cardboard box that accompanied the
Clydesdale Insert. Included are the surround panels,
assembly hardware, and surround mounting bracket.
Refer to the instructions included with the surroundfor complete assembly and installation.
Read this Owner’s Manual for all other installationand operational requirements.

Removing & Reversing the Door

Photo 18 - Reversible Door CatchTo reverse the door to open from the right, first cover
the ash lip cover with cardboard or a towel (to avoid
scratching it), then remove the door.
1. Open and support the door, then remove the machine
screw securing the upper inner hinge. Lift the door off
the lower, inner hinge section.
1.

Photo 19 – Reversible Door Stop
4.

Inner Hinge
SectionPhoto 16 – Upper Hinge Mounting Detail

Outer Hinge
SectionUse a hex wrench to remove the door catch and thescrews (and the door stop if present) on the right side.
5. Reattach the door catch on the opposite side of thefront, using the same screws. Reattach the screws(and door stop if present) on the left where the catch
was.
6. Remove the two Phillips head screws where thehinges will go on the left side – install them on the rightside.
7. Rotate both inner hinge sections 180 degrees andmount the lower hinge’s inner section on the left sideof the insert.
8. Rotate the door 180 degrees – you do not have to
remove or adjust the handle.
9. Insert the pin in the lower hinge’s outer section.
10. Insert the hinge pin in the upper hinge’s inner section
and place it on the upper outer hinge section still
attached to the door, reinstall any spacers.
11. Position the door so it is open about 80 degrees andplace it on the lower inner hinge section.
12. Attach the upper inner hinge section to the insert.
13. Tap the pins down to seat them if necessary.
14. Close the door and check its alignment – ensure it issquare in the opening, and that it does not drag on theash lip cover. Adjust the hinges/spacers if needed.
15. Check the gasket seal using the dollar bill test. Closethe door on a dollar bill – if the bill pulls out without any
resistance at any point; this is where it will leak, adjust
the door accordingly.

Photo 17 – Lower Hinge Mounting Detail2.

Remove the lower hinge section from the insert.

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Removing the Ash Lip Cover &FaçadeRear Notch

In some instances, it may become necessary to
remove the Façade or Ash Lip Cover. To remove the
Façade, you must first remove the Ash Lip Cover. To
service the blower, you must also remove the Ash Lip
Cover.
1.

To remove the Ash Lip Cover, loosen the two hex
socket head set screws securing the ash lip cover asshown in photo 20. In order to lift the ash lip cover, youmust loosen the set screws enough to clear themounting clips (see photo 21).

Ash Lip
Cover

Setscrews

Photo 23 – Top Grill Adjustment Point Detail3.

4.

The Top Grill on brown enamel finish Clydesdales
uses three adjustment points to keep the grill fromresting on the façade’s enamel surface. The draft port
plug (see photo 32), and two setscrews (see photo
above) are adjusted at the factory, but may needfurther adjustment after installation or maintenance.
Lift the Façade up slightly and tilt it towards you so themounting clips clear the lip on the stove body (seephoto 24). Carefully move the Façade away from theinsert and set aside.

Façade Clip (2)Set Screw (2)Photo 20 – Ash Lip Cover Detail
Ash Lip CoverMounting Clip (2)Leave exposed

Photo 24 – Façade Clip Detail (rear view)
Photo 21 – Ash Lip Cover Mounting Clip Detail2.

To remove the Façade, first remove the top grill (seephoto 22). On brown enamel Clydesdales, carefully lift
the grill straight up to avoid scratching or chipping the
façade’s finish.

5.

When ready, reinstall the Façade, Top Grill, and Ash
Lip Cover.

Note: The façade is correctly mounted when the clips
are positioned as shown in photo 24. Do not remountthe façade and place the mounting clip behind thesecond inner cast lip shown above.

Top Grill

Photo 22 – Top Grill

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Blower Power Cord Routing
The Clydesdale 8491 ships from the factory with theblower system’s power cord routed on the left side of
the insert as you face it. If your installation requires
the cord on the right side, you must remove the
façade and disassemble the ash lip assembly toaccess the wire clips to change the position of thepower cord.
1. Loosen Set Screw and remove Ash Lip Cover.
Remove the Façade as described on page 15.

4. Use a Phillips head screwdriver to remove thescrews securing the wire loops on the left andtransfer everything to the right side ensuring you
place the loops in the equivalent locations(arrows). A wire loop must be placed on thescrew closest to the corner to ensure the cord
does not rub on the blower housing. Do notdisconnect any wiring – there is more thansufficient length to route the cord to the right over
the top of the blower speed control.

Photo 28 – Wire Loop Mounting Detail

Photo 25 – Set Screw Detail
2. Remove screw and step bushing securing the aircontrol to the bracket.

5. Re-attach the ash lip assembly to the front of theinsert. Ensure the cord is not touching the blower
housing and is routed through the space above
the mounting flange. Ensure the cord is notpinched in any way. Re-attach the screw andstep bushing securing the air control to thebracket. Ensure the air control moves freely. Reinstall the façade and then the ash lip cover.

Photo 26 – Air Control Mounting Detail
3. Use a 1/2” socket, or wrench and remove the 4bolts and washers securing the Ash Lip
Assembly to the body of the insert. There is noneed to disconnect any wires.
Photo 29 – Correctly Routed Cord Detail

Photo 27 – Ash Lip Assembly Fastener Detail

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Clydesdale Fireplace Insert Model 8491

Venting Components & Configuration
Installing a Venting System
DO NOT CONNECT THIS UNIT TO ANY AIR
DISTRIBUTION DUCT OR SYSTEM

Secure all joints, including attaching the flue liner
to the Fireplace Insert's flue collar, with three
sheet metal screws. Install #10 x 1/2" (3 mm x 13mm) sheet metal screws into the holes pre-drilled in
the flue collar. Eliminating the screws can cause
joints to separate from the vibrations that result froma creosote chimney fire.
Remember, the NFPA has recommended minimum
clearances for chimney connectors to combustibles
such as walls and ceilings. Once the Fireplace Insert
is installed at safe distances from these combustible
surfaces, it is important to maintain these connector
clearances for the remainder of the installation.

Connecting Your Wood Fireplace
InsertYou can connect your Clydesdale to a prefabricatedmetal chimney or a masonry chimney. See Figure 6
for an example to aid in connections.
With all chimneys, a positive connection must
be made between the fireplace insert’s flue
collar and the chimney.
In an existing Masonry Chimney, use one of theapproved following methods:
In the U.S:
1. Connect the insert to a listed 6” stainless steel
flexible connector that connects to a listed 6”
stainless steel liner extending the full length ofthe chimney.


A 22 ga. or greater Blue Steel 6”
connector is also acceptable toattach to the flue liner.

2. Connect the insert to a listed 6” stainless steel
flexible connector that extends beyond thefireplace’s damper into an approved flue tile liner.
3. In all cases, a sealed block off plate, or a plug ofother noncombustible material such as unfaced
fiberglass insulation, must be installed at thedamper area of the existing fireplace to seal thechimney from the room air.

In Canada:
4. The fireplace insert must be installed with acontinuous chimney liner with a minimum
diameter of 6” extending from the fireplace insert
to the top of the chimney. The chimney liner must
conform to the class 3 requirements of chimney
liner standards can/ulc-s635 or can/ulc-s640.
Do not use aluminum or galvanized steel pipe
as a connector or chimney liner. Thesematerials are not suitable for solid fuelburning applications.

Connecting to a PrefabricatedMetal Chimney
You can install the Clydesdale in masonry or zeroclearance fireplaces. Before installing the stove in afactory-built fireplace, the fireplace must have thefollowing characteristics:
1) Listed per UL 127 or ULC S610.
2) Include a full height listed chimney liner meetingtype HT requirements (2100° Fahrenheit) per UL
1777 (United States) or ULC S635 (Canada)
standards.
3) The means to prevent room air passage to thechimney cavity of the fireplace.
4) Does not disturb the airflow in or within thefireplace when installed (louvers, or cooling air
inlet or outlet ports must not be blocked).
5) Not be altered in any way, except for thefollowing:a) External trim pieces which do not affect theoperation of the fireplace can be removed,
providing they are stored on or within thefireplace for re-assembly if the insert isremoved.
b) The chimney damper can be removed to
install the chimney liner.
6) Must not have blocked circulating chambers (ifavailable).
7) The means for removing the insert to clean thechimney flue.
8) Have a permanent metal warning label (provided
with the Clydesdale—see following illustration)
attached to the fireplace by riveting it to theoutside wall, stating that the fireplace must be
restored to its original condition for safe use
without the insert.

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Clydesdale Fireplace Insert Model 8491

Ensure the size of the chimney’s flue is appropriate
for this Fireplace Insert and that it is not too large.
Use a masonry chimney with a maximum 8" x 8" (203mm x 203 mm) tile size for best results. An oversizedflue will contribute to the accumulation of creosote.
Remember, you must adhere to all previously
described floor protection requirements when
installing into a zero clearance fireplace.
WARNING: DO NOT CONNECT THE FIREPLACE
INSERT TO A CHIMNEY FLUE SERVING ANOTHERAPPLIANCE.

Ensure the size of the chimney’s flue is appropriate
for the Clydesdale. The Clydesdale requires a 6"
(152 mm) inside diameter flue for new installations.
A 6” diameter flue provides adequate draft andperformance. You can use an 8" (203 mm) diameter
existing flue with a reducer. An oversized flue
contributes to creosote accumulation. (In this case,bigger is NOT better.)
There are two ways to install a prefabricated metalchimney:
An interior installation where the chimney passes
inside the residence through the ceiling and roof.
An exterior installation where the chimney passes
through the wall behind the Fireplace Insert thenup the outside of the residence.
Whenever possible, choose an interior chimney. Aninterior chimney heats quickly and retains its heat;thus promotes a better draft and discourages theformation of creosote. An exterior chimney does notbenefit from the surrounding warmth of the building,so it typically operates at lower flue temperatures
than an interior chimney. An exterior chimney’s draft
is not as strong and may experience increased
creosote accumulation.
REMOVE THE DAMPER OR LOCK IT OPEN.

Connection to a Masonry Chimney
Hire a professional to examine the masonry chimney
for cracks, loose mortar, and other signs ofdeterioration and blockage before connection. If thechimney needs repairs, complete them before
installing and using your Fireplace Insert. Do notinstall your Fireplace Insert until the chimney is safe
for use.
Ensure the chimney’s cleanout is complete andworking properly. To avoid a loss of draft, thecleanout must close off completely.

Use the following checklist to ensure that yourmasonrychimneymeets
theseminimum
requirements:
Chimney wall construction:
A brick, modular block, rubble or stone wall at
least 4" (102 mm) thick.
Flue liner:
Minimum ceramic flue liner thickness of 5/8" (16mm). Installed with refractory mortar and with atleast 1" (25 mm) air space.
An equivalent listed chimney flue liner systemmeeting type HT requirements or other approved
material.
Interior chimney requirements:
At least 2" (51 mm) clearance to combustible
structure
Fire stops installed at the spaces where thechimney passes through floors and/or ceiling.
Insulation must be 2" (51 mm) from the chimney.
Exterior chimney requirements:
At least 1" (25 mm) clearance to combustible
structure.
Chimney height requirements: (See page Error!
Bookmark not defined.)
At least 3 feet (0.9 m) higher than the highest
part of the roof opening through which it passes.
At least 2 feet (0.6 m) higher than any part of theroof within 10 feet (3 m) measured horizontallyfrom the top of the chimney. This Fireplace
Insert requires a minimum chimney height of 13
feet (4 m).
The maximum recommended
chimney height is 30 feet (9m).
IMPORTANT: You must seal the damper areaaround the chimney liner to prevent room airfrom entering the chimney cavity of thefireplace.
WARNING: DO NOT REMOVE BRICKSMORTAR FROM THE EXISTING FIREPLACE!

OR(Exception) Removal of masonry or steel (including
the damper plate) from the smoke shelf and adjacentdamper frame if necessary to accommodate achimney liner, provided their removal will not weaken
the structure of the fireplace and chimney, and will
not reduce protection for clearance to combustible
materials to less then required by the National
Building Code.

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Clydesdale Fireplace Insert Model 8491

Figure 6 – Connecting to a masonry chimney

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Clydesdale Fireplace Insert Model 8491

Figure 7 – The 2 / 10 / 3 Chimney Exit Clearance Rule

Figure 8 – Minimum Chimney Height Is 3’ Even At the Ridge

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Clydesdale Fireplace Insert Model 8491

Operation
WARNING: HOT WHILE IN OPERATION. KEEP
CHILDREN, CLOTHING AND FURNITURE AWAY.
CONTACT MAY CAUSE SKIN BURNS.

Please read this entire chapter before lighting yourfirst fire. It explains the controls and features of yourwood Fireplace Insert, how to choose firewood, burnrates, and how to break-in your Fireplace Insert anduse it on a daily basis.

Controls & Features
WARNING: ONLY OPERATE WITH DOOR FULLYOPEN OR CLOSED. IF DOORS ARE LEFT PARTLY
OPEN, GAS AND FLAME MAY BE DRAWN OUT OF
THE OPENING, CREATING RISKS FROM BOTH
FIRE AND SMOKE

primary air control. The control does not completely
stop the flow of air.

Operating the Blower
The blower is factory installed within the front ash lip.
The blower will run only when the insert is hot. The
blower control (notched wheel) is located in thebottom center of the ash lip (see Figure 9). Routing
the power cord to the left or right of the insert ispossible - follow the instructions provided in the
installation section.

IF OPERATING WITH DOORS FULLY OPEN, YOU
MUST USE THE ACCESSORY SCREEN AVAILIBLE
THROUGH YOUR HEARTHSTONE DEALER
DO NOT FORCE THE DOOR OPEN PAST THE
DOOR STOP OR YOU COULD DAMAGE THE
ENAMEL FINISH AND DOOR FRAME (ENAMELEDSTOVES ONLY).

If operating with the door open, some fuels may
create carbon monoxide, which can be hazardous or
fatal to your health. Do not burn anything but clean,
dry firewood
FRONT DOOR & LATCH: The front door allows you
to load wood into your Fireplace Insert; a fixed handle
allows you to operate the front door and allows you tolatch the front door closed. The front door isreversible (hinges moved to the left) to open from theright side. To open the door, lift the handle to the 10
o’clock (or 2 o’clock for RH opening door) position,and pull out on the door. To latch the door, push thedoor closed tightly then lower the handle to the 8o’clock (4 o’clock for RH opening door) position. Pulllightly on the door handle to ensure it is properly
latched. Do not force the door past the door stop
if present; you could damage the door frame andfinish.
PRIMARY AIR CONTROL: The control handle islocated on the front top center of the ash lip under theash lip cover (see Figure 9). The primary air control
allows you to regulate the amount of air entering thefirebox. Generally, the more air allowed into thefirebox, the faster and hotter the rate of burn;conversely, less air creates a slower burn. To fully
open the primary air intake, pull the handle as far out
as it will go away from the firebox; push the handle inas far as it will go towards the firebox to close thePrimary Air Control

Blower Speed Control

Figure 9 – Primary Air, & Blower Speed Controls

Choosing FirewoodYour Clydesdale Wood Burning Insert is designed toonly burn natural firewood - also known as cordwood.
CAUTION: DO NOT USE CHEMICALS OR
FLAMMABLE FLUIDS SUCH AS GASOLINE,
NAPHTHA, KEROSENE, CHARCOAL LIGHTER
FLUID OR ENGINE OIL TO START A FIRE. DO NOTUSE CHARCOAL, PELLETS, COAL, ARTIFICIALLOGS OR ANY OTHER MATERIALS AS FUEL;
THEY ARE NOT SAFE. DO NOT BURN GARBAGE.

The quality of your firewood affects heat output,
duration of burn and performance of your Fireplace
Insert. Softwoods generally burn hotter and faster,while hardwoods burn longer and produce more long
lasting coals. Density and moisture content are two
critical factors to consider when purchasing wood foryour Fireplace Insert.

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Clydesdale Fireplace Insert Model 8491

The following is a list of wood species and theirrelative BTU (British Thermal Unit) content. The
higher the BTU content the longer the burn.
Firewood with higher a BTU content is generally
considered ideal for a wood stove.

Wood Heat Value: Sorted By Btu
Content
Common NameLb/ cord

MBTU/ cord

4,728
4,327
4,267
3,890
3,890
3,890
3,832
3,832
4,100
3,712
4,012

32.9
27.7
27.3
26.8
26.8
26.8
26.7
26.7
26.5
25.8
25.7

3,757
3,757
3,757
3,689
3,689

24
24
24
23.6
23.6

3,150
3,112
3.112
3,247
3,247
3,179
3,179
3,192
3,120
2,880
2,880
3,052
3,052
2,808
2,992
2,924
2,900

21.8
21.6
21.6
20.8
20.8
20.3
20.3
20.2
20
19.9
19.9
19.5
19.5
19.5
19.1
18.7
18.1

High
Osage Orange (Hedge)
Hickory, Shagbark
Hop Hornbeam (Ironwood)
Beech, Blue (Ironwood)
Birch, Black
Locust, Black
Hickory, Bitternut
Locust, HoneyApple
Mulberry
Oak, White

Medium High
Beech, European
Maple, Sugar
Oak, Red
Ash, White
Birch, Yellow

MediumJuniper, Rocky Mtn
Elm, Red
Coffeetree, Kentucky
HackberryTamarack
Birch, Gray
Birch, White (Paper)
Walnut, Black
CherryAsh, Green
Cherry, Black
Elm, American
Elm, White
SycamoreAsh, Black
Maple, Red
Fir, Douglas

Medium Low
BoxelderAlder, Red
Pine, Jack
Pine, Norway (Red Pine)
Pine, Pitch
Catalpa
Hemlock
Spruce, Black
Pine, Ponderosa

2,797
2,710
2,669
2,669
2,669
2,360
2,482
2,482
2,380

17.9
17.2
17.1
17.1
17.1
16.4
15.9
15.9
15.2

2,290
2,100
2,100
2,100
2,236
2,236

14.7
14.5
14.5
14.5
14.3
14.3

2,104
2,108
1,984
2,108
1,913

14.1
13.8
13.8
13.5
12.2

Low
Aspen, American
Butternut (Walnut, White)
SpruceWillow
Fir, BalsamPine, White (Eastern,
Western)Fir, Concolor (White)
Basswood (Linden)
Buckeye, Ohio
Cottonwood
Cedar, White

Moisture content also plays a key role in theperformance of your stove. Wood freshly cut from aliving tree (green wood) contains a great deal ofmoisture. As you might expect, green wood has
difficulty burning and should be seasoned before
using it in your wood stove. To properly season
green wood: split, stack and allow to air dry for aperiod of one year.
Stack the firewood on skids or blocking to keep it off
the ground, cover only the top of the stack. Plastic or
tarps that cover the sides of the stack of wood trap
moisture and prevent the wood from drying. As forstacking, an old Vermonter said, "The spaces
between the logs should be large enough for amouse to get through, but not for the cat that'schasing it."
Do not store Firewood within the Fireplace
Insert's specified clearances to combustible
materials.

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Hearthstone’s Thermo-Ceramic
Baffle System
To enhance the combustion efficiency and reduce theparticulate emissions of the fire in your stove,
Hearthstone has developed an advanced THERMOCERAMIC baffle system. This system uses alightweight, durable ceramic material above thesecondary air tubes to maintain high temperatures inthe secondary combustion area to promote low
emissions and high efficiency combustion. This
material will not corrode, rust, dissolve, or lose its
strength, however it is vulnerable to puncture or
breakage due to rough handling.
Please Exercise Care When Loading Wood or
Cleaning Your Insert, To Not Damage the ThermoCeramic Baffle

Located directly above the air tubes in the top of thefirebox, this white or gray sheet of material will break
if wood or cleaning brushes impact it. Use care whenloading and cleaning your stove to avoid breaking
this material. If the baffle fractures or a hole ispunctured, the stove will function improperly. You
must replace the board through a qualified
Hearthstone dealer.

Building a Fire
Once you understand the controls of your Clydesdale
Fireplace Insert, and have chosen the appropriate
firewood, you are ready to start a fire.

Breaking in Your Wood Fireplace
Insert
It is imperative that you “break in” the Fireplace Insert
slowly. Cast iron must be "seasoned"; over-firing a
new Fireplace Insert may cause castings to crack or
may damage other Fireplace Insert parts. Slowly
driving the moisture out of the soapstone bricks lining
the firebox will minimize the “shock” to the stone at its
first exposure to high firebox temperatures.
When you light your first fires, the Insert will emit
some smoke and fumes. This is normal “off-gassing”
of the paints and oils used when manufacturing theFireplace Insert. If you find it necessary, open a few
windows to vent your room. The smoke and fumes
will usually subside after 10 to 20 minutes ofoperation. The odor and smoke will end once theFireplace Insert is “cured”.
The first fires may also produce other odors from
“impurities” that exist in the area immediately

Clydesdale Fireplace Insert Model 8491

surrounding the Fireplace Insert. Some of these
impurities are residues of cleaning solvents, paintsolvents, cigarettes, candle soot, pet hair, dust,
adhesives, a new carpet, and new textiles. Theseodors will dissipate over time. You can alleviatethese odors by opening a few windows or otherwise
creating additional ventilation around your Fireplace
Insert. If any odor persists, contact your dealer or an
authorized service technician.
If you adhere to the break-in procedure, as well as allother operating procedures in this manual, the castiron and soapstone firebox lining of your Fireplace
Insert will give you many years of trouble-free use.
Avoid the following conditions that can cause thesoapstone or cast iron pieces to break:Do not throw wood into the Fireplace Insert.
Do not use the door as a lever to force wood into
the Fireplace Insert.
Do not load wood that is encrusted with ice into aburning, hot stove as the thermal shock cancause damage.
Do not use a manufactured log grate. Burn thefire directly on the soapstone that lines thebottom of the firebox.
The bottom layer of soapstone in the firebox isintended to prevent thermal stress to the cast iron,and should remain in place at all times.
Do not over-fire the Fireplace Insert. (Refer topage 25).

Building a Break in Fire
1. Open the front door and place five or six double
sheets of tightly twisted newspaper in the centerof the firebox. Arrange kindling in a crisscrosspattern over the newspaper. Kindling should beapproximately ten pieces, 1/2" (13 mm) indiameter and 10" to 18" (254 mm to 457 mm)long.
2. Fully open the primary air control by pulling thecontrol handle fully out, away from the firebox.
3. Light the paper under the kindling. Leave thefront door slightly ajar momentarily until thekindling has started to burn and draft begins topull.
4. Close the door and allow the fire to burn. Keepthe front door closed while the Fireplace Insert isin use.
5. Keep a watchful eye on your fireplace insert tomaintain a steady, low-heat fire. Your first fireshould make the Fireplace Insert warm, but not

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hot to the touch. At most, add only a few small
chunks of wood to the fire to reach safe break-in
temperatures.
6. Once the Fireplace Insert is warm but not hot to
the touch, close the primary air control bypushing it in fully toward the firebox to allow thefire to die out completely.
7. Let the Fireplace Insert return to room
temperature.

Clydesdale Fireplace Insert Model 8491

When your room’s temperature is comfortable,
maintain your fire by loading smaller quantities ofwood. Burning smaller amounts of wood at a highburn rate creates the least amount of creosote in yourchimney, emits the lowest amount of pollutants, but
provides shorter burn times.

Your first fire and first fire each season thereafter
should be built and maintained as outlined above.
Your patience will be rewarded by a properly
seasoned Fireplace Insert.

Medium to Medium Low Burn Rate: In general, you
would usually create a medium to medium low burnrate, especially if your stove is left unattended
periodically. Set the primary air control to a mid-range
setting, appropriate to maintain a comfortabletemperature in the heated area. This setting
produces the most efficient overall burn.

Note: Because of the cool flue gas temperatures
present during the break-in procedure, creosote
may build up rapidly. Your door glass may also
get dirty. A good hot fire will clean it. We
recommend a visual inspection (and cleaning if
necessary) of your stovepipe and chimney oncethe break-in procedure is completed.

Low Burn Rate: Close the primary air control for a
low burn rate. This setting provides the longest burntime. However, set a low burn rate only periodically.
Over extended periods, a low burn rate promotes theaccumulation of creosote. If you consistently maintainlow burn rates, inspect your venting systemfrequently.

Operating Your Insert Efficiently
Hearthstone designed your Clydesdale insert to burnfirewood cleanly and efficiently. The following
operational tips explain how to obtain the most heatpossible with minimal creosote build-up and emitted
pollutants.

Burn Rate
There are four basic burn rates: high burn, medium
burn, low burn, and overnight burn. Each has its own
purpose.
High Burn Rate: We recommend a high burn rate
once or twice a day to fully heat the stove andchimney; this also helps keep the amount of creosote
in your stove and chimney to a minimum.
After the fire is established and both the stove andchimney are hot, create a high burn for maximum
heat output. Pull the primary air control out so that it’s
fully open or almost fully open. Fully load the fireboxwith wood on a bed of hot coals or on an actively
flaming fire.
After you have attained a high burn rate, monitor thestove temperatures frequently to ensure that thestove is not over-fired. The surface temperature on
top front of the insert (firebox body under grill) should
not routinely exceed 600°Fahrenheit (316°Celcius).
Once you understand how your insert burns andheats in your particular setting, you can easily createa high burn rate without risk to the stove or chimney.

Overnight Burn Rate: An overnight burn, as you
might expect, allows you to keep an area heated
while you sleep. To create an overnight burn, firstensure the stove and chimney is hot from anestablished fire. Next, pull the primary air control fully
open, and then completely load the firebox withwood. Remember, larger pieces of wood burn longer.
Allow the fire to burn intensely for 20 to 30 minutes.
Finally, push the primary air control close to its lowest
setting; the fire will settle into a lower burn rate with asmall flame and more secondary gas ignition. The fire
will now burn slowly and steadily. The longevity andintensity of the fire depends on the type, size andquality of the wood, the strength of the chimney draft,
and other variables that vary from installation to
installation. High draft installations or situations may
require using a low burn rate setting.
In the morning, you should find a bed of hot coals
buried within the ashes. The insert should be warm to
the touch but not hot. To restart the fire without
relighting, simply stir and rake the ashes with a poker
until the hot coals have come to the surface. Place a
handful of kindling and a few small logs on the coals,
close the door, and fully open the primary air control.
The fire should re-ignite within 5 to 10 minutes. Oncethe fire is burning well, add a few larger logs, closethe door, leave the primary air control fully open, andallow the fresh logs to ignite.
Running a high burn rate at least once a day burns
off accumulated creosote from within the insert andPage 24 of 33

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venting system. Now, in the morning after an
extended low burn rate, is a good time to create yourdaily high burn rate; run it for about 20 minutes or so.
Not only does this hot fire promote a clean stove andchimney, it also helps keep the glass cleaner for easy
viewing of the fire within.
Once the fire is burning briskly, regulate the primary
air control to a medium setting for a medium, tomedium low burn rate.

Intermittent Operation
If your Fireplace Insert is not used continuously or
has not been used in quite some time, follow the
break-in procedure at least once to minimize thestress of a hot fire on a cold Fireplace Insert before
proceeding with normal operation. We recommend
one break-in fire at the start of each heating season.

Building a Fire for Everyday Use
1. Open the front door and place five or six double
sheets of tightly twisted newspaper in the centerof the firebox. Arrange kindling in a crisscrosspattern over the newspaper. Use about tenpieces of kindling approximately 1/2" (13 mm) indiameter and 10" to 18" (254 to 457 mm) long.
You can place two or three small logs on top of
the kindling if desired.
2. Fully open the primary air control by pulling thecontrol handle fully out, away from the firebox.
3. Light the paper under the kindling. Leave thefront door slightly ajar until the kindling starts toburn and draft begins to pull.
4. Close the door and allow the fire to burn.
5. If you did not add small logs in step 1, do so once
the kindling is burning well. Open the front door
and add small logs. Ensure you keep the logs
away from the glass in front in order for the airwash system to work properly. Otherwise, keep
the door closed while the insert is in use.
6. Once the fire is burning well, add larger woodpieces to build the fire up. Use the primary aircontrol to regulate the desired rate of burn. Pull
the handle out to open the PRIMARY AIR
CONTROL for a high rate of burn; push it in to
reduce the primary air for a lower rate of burn.
Note: When opening the front door to reload
or re-arrange logs, open the door just a crack
first, pause for a moment, then open the door
completely. This procedure allows the firebox

Clydesdale Fireplace Insert Model 8491

to clear of smoke before the door opens fully.
Also, reloading on a bed of hot, red coals
reduces smoking time and will bring fresh fuelup to a high temperature rapidly.

Disposal of Ashes
Place ashes in a metal container with a tight fitting lid.
Place the closed container of ashes on a noncombustible floor, or on the ground outside, wellaway from all combustible materials or fumes,
pending final disposal. If ashes are disposed of byburial in soil or otherwise locally dispersed, retain
them in the closed container until all cinders havethoroughly cooled.

Over-Fire Caution
Over-firing means the Fireplace Insert is operating attemperatures above the recommended temperatures
outlined above in the BURN RATE section. Carefully
avoid over-firing since it will cause damage to theFireplace Insert. Symptoms of over-firing include
short burn times, a roaring sound in the Fireplace
Insert or chimney, and discoloration of the finish.
Over-firing can be caused by excessive draft,inappropriate fuel, and operator error. Correct anover-fire situation as follows:
EXCESSIVE DRAFT: Contact your dealer to have adraft reading taken.
INAPPROPRIATE FUEL: Do not burn coal; kiln dried
lumber, pellets, wax logs, plastics, trash or anythingother than natural cordwood.
OPERATOR ERROR: Ensure all the gaskets are ingood condition. Replace worn out or compressedgaskets. Do not burn the Fireplace Insert with thefront door in a partially open position. The door mustbe fully closed or opened completely (e.g. whenusing viewing screen).
If you suspect that your Fireplace Insert is over-firing,
contact your dealer immediately. Damage done byover-firing is not covered by your warranty.
Results of over-firing can include: warped or burned
out internal parts, cracked firebox soapstone,
discolored or warped external parts, and damaged
enamel.
NOTE: ANY SYMPTOMS OF OVER-FIRING WILL
VOID YOUR WARRANTY!

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Clydesdale Fireplace Insert Model 8491

Maintenance
Creosote Formation and Need for
RemovalWood, when burned slowly, produces tar and otherorganic vapors, which combine with expelled
moisture to form creosote. These creosote vapors
condense in the relatively cool chimney flue of aslow-burning fire. As a result, creosote residue
accumulates on the flue lining. When ignited, thiscreosote makes an extremely hot fire, which may
damage the chimney or even destroy the house.
Inspect the flue liner and chimney at least once every
month during the heating season to determine if there
is a creosote buildup.
To prevent the buildup of creosote:
1. Burn the Fireplace Insert with the primary aircontrol fully open for 20 - 40 minutes daily toburn out creosote deposits from within theFireplace Insert and the venting system.
2. After reloading with wood, burn the Fireplace
Insert with the primary air control fully open
for 20 to 30 minutes.
This manner ofoperation ensures early engagement of thesecondary combustion system which, whenengaged, minimizes creosote buildup in thechimney.
If a creosote residue thicker than 1/4" (6 mm)accumulates, remove it to reduce the risk of achimney fire.
If your glass always remains dirty, your operating
temperatures are probably too low, or your wood is
not dry enough; therefore, there is a higher risk ofcreosote buildup.
Inspect the venting system for creosote at the Insert
connection and at the chimney’s top.
Coolersurfaces tend to build creosote deposits faster, so it
is important to check the chimney at the top (where it
is coolest) as well as from the bottom at the Insert.
Remove accumulated creosote with a cleaning brushspecifically designed for the type of chimney in use.
Use a certified chimney sweep to perform thisservice. Contact your dealer for the name of acertified chimney sweep in your area (your dealer
may be a certified sweep!).
We recommend that you have the entire systemprofessionally inspected, cleaned, and repaired if
necessary, before each heating season.

Gaskets
Depending on use, replace gasket materials every
two to three seasons. If the door seal is leaking, a
new gasket will assure a tight seal and improved
performance. Contact your dealer for a gasket kit
that includes instructions and gaskets for yourFireplace Insert.
To replace the door gasket, first remove the oldgasket with a utility or putty knife. Clean all gasket
channels with a wire brush. Apply gasket cement tothe channels and push the new gasket into place
without stretching the gasket material. Immediately
close the door to fully press the gasket into place andassure a positive seal.

Glass
Do not operate the Fireplace Insert with a broken
door glass. Do not abuse the front door by striking or
slamming.
When necessary, clean the glass with low alkalinecontent commercial stove glass cleaners, which areavailable from your local dealer. Never attempt toclean the glass while the fire is burning, or if the glass
is hot. Most deposits are easily cleaned by following
the instructions provided with the cleaner. To cleanheavier deposits, remove the door from the Fireplace
Insert (take care to save hinge pins and spacers forreuse). Lay the door face down on a workbench ortable with the handle hanging over the edge. Apply
the cleaner to the glass and allow it to sit for a few
minutes. Placing the door flat, it will allow the cleaner
to penetrate rather than running off the surface of theglass. Wipe the cleaner off with a soft cloth.
Important: scratching or etching the glass
will weaken the integrity of the glass. Do not
use a razor blade, steel wool, or any otherabrasive material to clean the glass. Use low
alkaline content cleaners only.
The front door glass is a ceramic, shock-resistantglass, made specifically for use in woodstoves. Do
not use any replacement glass other than theceramic glass manufactured and supplied for use inthis woodstove. Replacement glass is available
through your local dealer.
Replace the door glass immediately if broken.
Contact your local dealer for a replacement glass kit.
The glass kit comes with instructions and everything

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Clydesdale Fireplace Insert Model 8491

needed for the repair. If you replace the glass
yourself, wear work gloves and safety glasses.
Door removal and glass and glass gasket
replacement procedure is as follows: Refer toFigure 10.
1. Cover the Ash Lip Cover with cardboard oran old towel to avoid scratching it.
2. Remove the door by opening it about 45
degrees, support the door and remove thebottom hinge pin, then lift the top hinge pin
until it clears the door hinge section. Movethe door out and away from the insert.
3. Place the door face down on a flat, smoothsurface.

4. Apply penetrating oil to the screws. Remove
the screws to separate the glass retainerfrom the door.
5. Carefully lift the damaged glass from thedoor casting and discard.
6. Replace the screws.
7. Install the door.
WARNING: DO NOT USE SUBSTITUTE MATERIALSWHEN REPLACING THE GLASS OR ANY DOORCOMPONENTS.
USE
ONLY
AUTHORIZEDHEARTHSTONE COMPONENTS.

Glass specifications: 320mm x 583mm x 5mm (125/64” x 22-15/16” x 0.197”) Neoceram.

Figure 10 – Glass Replacement Components

Cast Iron
Exterior cast iron parts are either painted with black,high-temperature stove paint or porcelainized withenamel finishes in various colors.
Use black, high-temperature stove paint (werecommend satin black by Stove Bright) to touch up
and maintain the original appearance of painted castiron. Use a damp sponge to wipe clean. Dry the castiron thoroughly to prevent rusting.
Clean enameled castings with a standard glasscleaner. With time and use, a very fine, subtle
network of lines, commonly known as crazing, may
appear seemingly beneath the surface of the enamel.
Crazing is a natural predictable process and does not
represent a flaw.

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Clydesdale Fireplace Insert Model 8491

Blower System
For maximum efficiency, the blower system will require periodic cleaning to remove dust that will accumulate
during normal use. To access the blower system, you must remove the Ash Lip Cover as described in the
installation section of this manual.
Remove the Ash Lip Cover and carefully vacuum components. Take care to avoid bending the fins on theblower fans. Inspect all wiring and mounting hardware for damage or deterioration.

Photo 30 – Blower System (Ash Lip Cover Removed)

1

2

3

4

Photo 31 – Blower Kit Major Components (Kit 94-57910)
1.
2.
3.
4.

Left Blower Fan Assembly
Right Blower Fan AssemblyPower Cord
Speed Control with Bracket

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Clydesdale Fireplace Insert Model 8491

Troubleshootingb.

Basic Heating Issues
Virtually all woodstove operators experience basic
common problems at one time or another. Most are
correctable and generally require only a minor
adjustment of the stove, installation, or operating
technique.
In cases where weather conditions
dramatically affect stove performance, the problems
are typically temporary and resolve themselves once
the weather changes.
Keep in mind that your house itself regulatesroom/house temperatures. How well the walls, floors
and ceilings are insulated, the number and size ofwindows, the tightness of exterior doors, and theconstruction or style of your house (vaulted ceilings
or other open spaces which collect large percentagesof heat, ceiling fans, etc.) all are determining factorsof room temperature.
Your Insert's performance is also greatly dependanton its installation. One common cause of poor
performance is inadequate draft. An oversizedchimney flue is commonly the cause. Oversized
flues result in decreased vacuum, which prevents thesmoke from rising out the chimney. Oversized flues
are also more difficult to heat effectively, especiallywhen burning a high efficiency insert like the
Clydesdale.
Cool flue temperatures inhibit theestablishment of a strong draft (and encourage
accumulation of creosote). The lack of a strong draft
will cause the fire to die down and may even force
smoke into the room. If your chimney is the proper
size and a strong draft is not easily established, thereis the possibility the chimney is just too cold. Again,
hot chimneys promote a stronger draft. Other draft
issues and guidelines are as follows:
1.

AN "AIRTIGHT" HOUSE:
a. Inadequate infiltration air supply in a superinsulated or especially well sealed home.
b. Air starvation exacerbated by exhaust fans,such as clothes dryers, bathroom vent fans, orcook stove exhaust fans.

2.

TALL TREES OR BUILDINGS:
a. These obstructions, in close proximity to the
top of the chimney can cause chronic or
occasional downdrafts.
b. Consider the placement of other objects whenselecting a site for a new chimney.

3.

WIND VELOCITY:
a. Strong, steady winds generally create a strong(better) draft.

“Gusty" wind conditions may cause erratic
downdrafts. Strong winds can produce anegative pressure condition in the upwind side ofa structure.

4.

BAROMETRIC PRESSURE:
a. Chimney drafts are typically sluggish on balmy,
wet or muggy days (low or falling barometricpressure). This is generally self-correcting as
the weather changes.

5.

BRISKNESS OF FIRE:
a.

6.

SEASONAL FACTORS:a.

7.

The hotter the fire, the hotter the chimney and,
therefore, the stronger the draft.

Early fall and late spring are generally difficult
seasons in which to establish proper drafts. The
colder the outside air is (relative to room
temperatures) the stronger the draft.

OPERATING THE FIREPLACE INSERT:a.

There are days when a draft is just not easily
established. As outlined above, seasonal factors
or a cold chimney may be the cause.

b.

Starting the fire using small kindling and small
wood pieces to obtain a quick, hot fire. Tend thefire frequently with small pieces until the chimney
is hot and the draft is well established.

c.

Briefly partially open a window in the room with
the insert to help establish a draft quickly.

Draft Sampling Access PortThe draft sampling port is located under the top grill
on the front center of the stove’s body. Remove thebolt or setscrew and nut to check the draft reading.
Ensure you replace the plug when finished.

Used on Matte &Blue-Black Enamel

Used on Brown
Enamel only

Photo 32 – Draft Port Detail

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Hearthstone

Clydesdale Fireplace Insert Model 8491

Troubleshooting Guide
PROBLEMPOSSIBLE CAUSESOLUTIONSINSERT SMOKES

Operating TechniqueFully open the primary air control one minute before opening
door. Open front door slightly until firebox clears of smoke, thenopen fully.
Preheat the chimney when first starting a fire.
Turn off all exhaust fans in home. Open window in room withunit until draft is established.
Examine the chimney liner and cap for blockage or creosote
accumulations. Check top of baffle for accumulated flue ash.
Reline the chimney to the appropriate diameter
Install a draft inducer or replace the chimney.
Lengthen the chimney.
Ensure metal flue liner extends the full length of chimney and isconnected securely to the flue collar. Or, with masonry liner,
ensure flue connector is sealed tightly to inside of chimney
where it passes through the fireplace damper area.
Seal all chimney and liner connections and any openings in or
around clean-out doors.
Disconnect all other appliances and seal openings.

Cold Chimney
Reverse Draft at Startup
Blocked Flue
Oversized Chimney
Undersized Chimney
Chimney Too Short
Incorrect installation

Air Infiltration Into Chimney

BACK-PUFFING ORGAS EXPLOSIONSUNCONTROLLED ORSHORT BURN

More Than One Appliance
Connected to the Flue
Operating Technique
Extra Low Burn Rate
Using accelerant
Chimney Down-draft
Excessive Ash Build-up
Unsealed or Open Door
Primary Air Control not
operating properly

INSUFFICIENT HEAT

Deteriorated Gasket Seals
Extra Long Chimney
High Winds or Hilltop
Location:
Oversized Chimney
Over-Fire Damage
Poor Quality or Green Wood
Burn Rate Too Low
Blocked Flue
Air Insulated Chimney

DIRTY GLASSBLISTERING OF
ENAMEL CASTING

Cold Exterior Chimney
Leaky flue connector or
Chimney liner
Too Much Heat Loss FromHouse
Poor Quality or Green Wood
Burn Rate Too Low
Leaky flue connector or
Chimney Liner
Operating Technique
Excessive Draft

Fully open the primary air control one minute before opening thedoor and keep it fully open for a few minutes after reloading.
Burn the Fireplace Insert at a higher burn rate.
NEVER use accelerants to start or invigorate the fire.
Install a chimney cap. Check chimney installation
Empty ashes more frequently.
Close the door tightly or replace the gaskets.
Ensure Primary Air control shutter is opening and closing whencontrol lever is moved. Note: Shutter is not designed to closecompletely.
Reseal the Insert body with new gaskets where necessary.
Shorten the chimney. Install a damper/restrictor in flue.
Install a chimney cap.
Reline the chimney to the proper diameter.
Inspect unit – replace damaged or warped components.
Use only air-dried wood, preferably dried at least one year.
Operate the Insert at a higher burn rate.
Examine the chimney liner and cap for blockage or creosote
accumulations. Check top of baffle for excessive flue ash.
Replace with a pre-fabricated insulated chimney system or aproperly sized and lined masonry chimney.
Reline or insulate the chimney.
Check the installation – ensure connector is securely attached
to flue collar. Check liner joints.
Caulk windows, seal openings in home. Increase energy
efficiency of home.
Use only air-dried wood, preferably dried at least one year.
Operate the Fireplace Insert at a higher burn rate.
Check the installation – ensure connector is securely attached
to flue collar. Check liner joints.
Do not over-fire the Insert. Monitor Insert temperatures. Use
seasoned cord wood only.
Check gasket seals. Check chimney height. Install flue
damper/restrictor. Install chimney cap.

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Hearthstone

Clydesdale Fireplace Insert Model 8491

Replacement Parts & Optional AccessoriesPART
NUMBER:DESCRIPTION:CASTINGS:*
2410-901
2410-905
2410-910
2410-915
2410-926
2410-927
2410-940
2410-946
2410-947
2410-951
2410-955
2410-960
2410-965
2410-970
2410-975
2410-991
2410-993
2410-994

BOTTOM
BACK
LEFT SIDERIGHT SIDE
ASH LIP/BLOWER HOUSING, FRONTASHLIP/BLOWER HOUSING, TOP
PRIMARY AIR MANIFOLDFRONTCASTING, DOORFRONT FAÇADE
SECONDARY AIR PLENUM CONNECTORSECONDARY AIR PLENUM, LEFTSECONDARY AIR PLENUM, RIGHTTOPFLUE COLLARSURROUND, STRAIGHTSURROUND, LEFT
SURROUND, RIGHT

KITS:
94-57910
7000-130
7000-135
7200-601
7211-946
7211-947
94-58910
3030-049
3160-080
5491-046
94-58912
3110-051
94-71910
2410-948
3900-190
94-73910
5491-045
5491-048

BLOWER ASSEMBLY KITGROMMET, SILICONESLEEVE, GROMMETCONTROL, SPEED, BLOWER
FAN, BLOWER, RT
FAN, BLOWER, LT
GLASS KIT
CLYDESDALE GLASSGASKET TAPE, ADHESIVE BACKRETAINER, GLASSDOOR GASKET KITGASKET ROPE, LOW DENSITY, ½”
DOOR HANDLE KIT
HANDLE, DOORKNOBFRONT DOOR LATCH KITCATCH, LATCH
LATCH

PART
NUMBER:STEELPARTS:
5470-039
5490-010
5940-012
5940-013
5940-014
5490-020
5490-050
5490-055
5490-058
5490-059
5490-071
5490-072
5490-073
5490-074
5490-075
5490-080
5491-011
5491-012
5491-013
5491-014
5491-015
5491-027
5491-030
5491-035
5491-043
5491-085
5491-087
7000-301

LEVEL, SURROUNDAIR SHROUD, BOTTOMPRIMARY AIR CONTROLPRIMARY AIR GATEPRIMARY AIR GATE CAP
SURROUND CLIP
STONE CLIP, REAR
STONE CLIP, SIDECOLLAR, PLENUM, SEC., LEFTCOLLAR, PLENUM, SEC., RIGHTSECONDARY AIR TUBE #1
SECONDARY AIR TUBE #2
SECONDARY AIR TUBE #3
SECONDARY AIR TUBE #4
CLIP, BAFFLE
BAFFLE SUPPORT S.S.
SHROUD
CLIP, ASHLIP COVER
HANDLE, AIR CONTROLWHEEL, SPEED CONTROL
BRACKET, SPEED CONTROL
BRACKET, BLOWER, RIGHT
BRACKET, BLOWER, LEFTSCREEN, ASHLIP
PLATE, CONNECTOR, SRRNDHINGE, DOORSLIDING BRKT, SURROUND
SNAP DISCSOAPSTONE:
1-0000-101
1-0400-900
1-0400-901
1-0400-902

STONE, REF, 4.5”x9x1.25”
STONE, REF, 4.5”x12”
STONE, REF, 4.5”x11.25”
STONE, REF, 4.5”x4.5”

MISC:
3120-490
3300-617
3300-618

BOARD, CERAMIC, BAFFLE, CLY
RATING LABELEPA HANG TAG, CLYDESDALE

94-79700
94-69900
94-5990010

Mantle Shield
Screen Kit
Matte Surround Extension

DESCRIPTION:*All are matte part numbers.

Clydesdale Accessories:
94-5991110
94-5970610
94-5970659

Matte Surround Kit
Matte Surround Caps
Blue/Black Enamel Surround Caps

Page 31 of 33

Safety Label

Page 32 of 33

WARRANTY REGISTRATIONThe Original Purchaser can complete their warranty registration on our website at www.hearthstonestoves.com,
or send a completed and signed Warranty Registration Form, which is enclosed in the Woodstove warranty
packet, to the following address:
Hearthstone Quality Home Heating Products, Inc.
Warranty Department
317 Stafford Avenue
Morrisville, VT 05661
NOTE: SENDING IN THE SIGNED WARRANTY REGISTRATION FORM IS NOT REQUIRED AS A
CONDITION OF WARRANTY COVERAGE OR HEARTHSTONE’S PERFORMANCE.

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