Topical Fire Research Series Volume 6, Issue 3 / November 2006

Heating Fires in 

Residential Buildings

Findings:

The decline in the incidence of heating fires has been dramatic. Over the past 20 years, the estimated number of residential building heating fires has fallen from 200,000 to 49,000 in 2004.

Heating fires are the second leading cause of all residential building fires (behind cooking fires).

Confined heating fires, those fires confined to chimneys, flues, fuel boxes, or boilers, account for 86% of 

residential building heating fires.

Heating fires due to electrical failures are more prevalent in multifamily homes than in one- and two-family 

residences.

Over one-quarter of residential building heating fires result from improper maintenance of heating equipment, specifically the failure to clean the equipment.

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Between 2002 and 2004, an annual average of 49,100 heating fires occurred in residential buildings and 

were responsible for an estimated 125 civilian fire deaths, 

575 injuries, and $232 million in property loss.1, 2 The 

term heating fires applies to those fires that are caused by 

functioning or malfunctioning central heating units, fixed 

or portable local heating units, fireplaces, heating stoves, 

chimneys, and water heaters.3 This topical report examines 

the causes and characteristics of heating fires that occur in 

residential buildings.

Data from the National Fire Incident Reporting System 

(NFIRS) (2002-2004) show losses from residential building 

heating fires are lower than those averaged across all building fires (Table 1).4

 When the small-loss, confined-heating 

fires are segregated out, the loss per fire for non-confined 

heating and non-confined, nonheating fires is nearly equal; 

deaths and injuries per thousand fires, however, are slightly 

higher for non-confined heating fires (Table 2). For confined heating fires in residential buildings – those fires 

confined to a chimney, chimney flue, fuel burner, or boiler 

malfunction – the loss per fire is nearly twice that of residential building, nonheating confined fires, while the injury 

rate is quite small (Table 3). As deaths are a rare occurrence 

in confined fires, the death rates across these groupings are 

minimal and virtually indistinguishable.

Table 1. Loss Measures for Building Fires (buildings, 3-year average 2002-2004)

Measure All Building Fires

Residential Building Fires

All Fires Nonheating Fires Heating Fires

Loss per Fire $19,011 $15,334 $16,849 $5,027

Injuries per 1,000 Fires 29.9 32.7 36.1 10.6

Deaths per 1,000 Fires   5.3   6.2   6.9   2.0

Note: Loss per fire is computed for only those fires where loss information was provided

Source: 2002-2004 NFIRS 5.0 data

U.S. Department of Homeland Security • U.S. Fire Administration

National Fire Data Center • Emmitsburg, Maryland 21727

www.usfa.dhs.gov/statistics/reports/pubs/tfrs.shtm 
TFRS Volume 6, Issue 3 / Heating Fires in Residential Buildings Page 2

Table 2. Loss Measures for Non-confined Building Fires5 (buildings, 3-year average 2002-2004)

Measure All Non-confined 

Building Fires

Residential Non-confined Building Fires

All Fires Nonheating Fires Heating Fires

Loss per Fire $30,349 $25,872 $25,872 $25,884

Injuries per 1,000 Fires 44.4 51.5 51.2 59.8

Deaths per 1,000 Fires   9.0 11.2 11.1 13.9

Note: Loss per fire is computed for only those fires where loss information was provided

Source: 2002-2004 NFIRS 5.0 data

Table 3. Loss Measures for Confined Building Fires6 (buildings, 3-year average 2002-2004)

Measure All Confined 

Building Fires

Residential Confined Building Fires

All Fires Nonheating Fires Heating Fires

Loss per Fire $469 $349 $282 $531

Injuries per 1,000 Fires 8.9 9.2 11.4 2.6

Deaths per 1,000 Fires 0.1 0.1   0.1 0.1

Note: Loss per fire is computed for only those fires where loss information was provided

Source: 2002-2004 NFIRS 5.0 data

Leading Causes of Residential Building Fires

Heating (19%) is second only to cooking (47%) as the 

leading cause of residential building fires (Figure 1). In 

the late 1970s and early 1980s, heating was actually the 

leading cause, due to a surge in the use of alternative 

space heaters and wood heating. This surge was stimulated in large part by an energy shortage and environmental concerns. While the overall number of fires in the 

Nation has decreased nearly 50% over the past 25 years, 

the decline in the incidence of heating fires has been 

dramatic. In 1983, there were nearly 200,000 heating 

fires7; by 2004 that number had fallen to approximately 

49,000.8

Figure 1. Leading Causes of Residential Building Fires

(percent of fires, 3-year average 2002-2004)

Source: 2002-2004 NFIRS 5.0 data

continued on next page
TFRS Volume 6, Issue 3 / Heating Fires in Residential Buildings Page 3

When Heating Fires Occur

Figure 2 shows the pattern of heating fires throughout the 

year. As would be expected, heating fires begin to increase 

during the fall and continue the increase through the winter. They are most prevalent during the winter months of 

December through February when the use of central heating systems, portable heaters, and fireplaces is most common. The peak month for residential building heating fires 

is January, with a decline through the remainder of the winter season and into the early spring. Despite the increased 

use of heating equipment, heating fires still remain the second leading cause (behind cooking) of residential building 

fires in the fall and winter months.

Figure 2. Residential Building Heating Fires by Month of Occurrence

(residential buildings, 3-year average (2002-2004) NFIRS 5.0 data)

Note: Adjustments were made for heating stoves: NFIRS 5.0 data on item first ignited (cooking materials) suggested the equipment involved in ignition 

was a cooking stove. These 558 incidents were excluded from this analysis.

Source: 2002-2004 NFIRS 5.0 data

Residential building heating fires are lowest in the early and outside temperatures decrease, heating equipment and 

hours of the morning (Figure 3). As people awaken to begin systems are used more heavily. Correspondingly, residential 

their daily activities, heating fires increase and hold constant building heating fires increase in the late afternoon and 

during the morning and midday. As twilight approaches peak between 6 p.m. and 8 p.m.

Where Heating Fires Occur – Type of Residence and Type of Incident

One- and two-family residences are disproportionately rep- sionally maintained heating systems may account for these 

resented in residential building heating fires. Heating fires differences in fire incidence. The remainder of residential 

in one- and two-family residences account for 81% of resi- building heating fires (4%) occur in hotels, dormitories, 

dential building heating fires while only 68% of current U.S. and other miscellaneous residential properties.

housing stock is single family housing.9

 Multifamily dwell- Eighty-six percent of residential building heating fires ings, 32% of the housing stock, account for an additional are confined heating. These are fires that are confined to a 15% of these heating fires. That most multifamily dwellings chimney or flue or are the result of a fuel burner or boiler (apartments, condominiums, and the like) have profes- continued on next page
TFRS Volume 6, Issue 3 / Heating Fires in Residential Buildings Page 4

Figure 3. Residential Building Heating Fires by Time of Day

(residential buildings, 3-year average (2002-2004) NFIRS 5.0 data)

Note: Adjustments were made for heating stoves: NFIRS 5.0 data on item first ignited (cooking materials) suggested the equipment involved in ignition was 

a cooking stove. These 558 incidents were excluded from this analysis.

Source: 2002-2004 NFIRS 5.0 data

malfunction and ar 10 e contained to the fuel burner or boiler. family) but because heating fires in one- and two-family 

Confined residential building heating fires occur in roughly residences dominate the numbers of fires, these confined 

the same proportion across the major residential property fires occur primarily there.

types (86% for one- and two-family and 87% for multiEquipment Involved in Heating Fires

Figure 4 illustrates the leading types of equipment involved (53%). Furnaces, both central heating units and local room 

units, account for 35% of residential heating fires. When 

these small fires are excluded, furnace fires are the largest 

proportion of heating fires.

in residential heating fires. When small, confined fires are 

included, chimneys are by far the largest source of residential heating fires, accounting for more than half of these fires 

Figure 4: Leading Equipment Involved in Ignition of Residential Building Heating Fires

(residential buildings, 3-year average (2002-2004) NFIRS 5.0 data)

Note: Adjustments were made for heating stoves: NFIRS 5.0 data on item first 

ignited (cooking materials) suggested 

the equipment involved in ignition was a 

cooking stove. These 558 incidents were 

excluded from this analysis.

Source: 2002-2004 NFIRS 5.0 data
TFRS Volume 6, Issue 3 / Heating Fires in Residential Buildings Page 5

What is Ignited?

When specific information is provided, the leading items 

ignited in heating fires are structural framing; film, residue, 

including paint and resin; and electrical wire (Table 4). 

There are variations, however, depending on the particular 

heating equipment involved. For example, fires involving heaters are more likely to involve bedding than other 

heating sources, and masonry chimneys are more likely to 

involve residues of resin, also known as creosote.

Table 4. Item First Ignited in Residential 

Building Heating Fires

(where data provided, residential buildings, 3-year average 

(2002-2004) NFIRS 5.0 data)

Item First Ignited Percent

Structural member or framing 10.2

Film, residue, including paint and resin   9.9

Electrical wire, cable insulation   6.6

Note: Adjustments were made for heating stoves: NFIRS 5.0 data on item first 

ignited (cooking materials) suggested the equipment involved in ignition was a 

cooking stove. These 558 incidents were excluded from this analysis.

Source: 2002-2004 NFIRS 5.0 data

Why Does the Fire Start?

As illustrated in Figure 5, three factors play a leading 

role in the ignition of residential building heating fires 

– operational issues, misuse of the heating equipment, 

and mechanical failures. Thirty-seven percent of residential building heating fires are attributed to some form of 

operational deficiency. Failure to clean heating equipment 

(primarily chimneys, fireplaces, and fireplace and heating 

stoves) accounted for nearly three-quarters (73%) of this 

category, or slightly over a quarter of all residential heating 

fires (27%). Misuse of heating equipment accounted for an 

additional 23% of residential heating fires. Placing combustible items too close to the heat source (primarily portable 

heaters and water heaters) accounted for the majority 

(71%) of this misuse. Twenty-one percent of residential 

building heating fires were the result of mechanical failures 

or malfunctions, over half of which (53%) were unspecified 

failures or malfunctions.

Figure 5. Factors Contributing to the Ignition of Residential Building Heating Fires

(where data provided, residential buildings, 3-year average (2002-2004) NFIRS 5.0 data)

Note: Adjustments were made for heating stoves: NFIRS 5.0 data on item first ignited (cooking materials) suggested the equipment involved in ignition was 

a cooking stove. These 558 incidents were excluded from this analysis.

Source: 2002-2004 NFIRS 5.0 data
TFRS Volume 6, Issue 3 / Heating Fires in Residential Buildings Page 6

Approximately one-third of heating fires that specify factors contributing to the ignition of the fire involve some 

kind of mechanical or electrical failure (31%). The reason 

for that failure varies, depending on the type of residential 

property involved in the fire. In both one- and two-family 

residences and multifamily residences, 20 to 26 percent of 

heating fires are due to mechanical problems (20% for oneand two-family; 26% for multifamily). In contrast, electrical problems are more prevalent in multifamily residences 

(22% versus 8% for one- and two-family residences).

Civilian Fatalities

Heating is the fourth leading cause of overall residential 

building civilian fire deaths, following arson, smoking, and 

open flame. When analyzed further, however, heating fires 

in residential buildings, along with children playing fires, 

are more likely to have multiple fatalities than other causes 

of fatal fires. In the case of residential building heating fires, 

half these fatal fires occur between midnight and 6 a.m., 

when the victims were sleeping. 

Alternative Heat Sources

Some fires are not necessarily coded as heating fires. A 

deadly phenomenon is that of fires caused when people use 

alternative sources of heat (such as a stove) to keep warm. 

This practice may be more common in impoverished areas 

where people may not be able to afford heating fuel and, 

instead, rely on space heaters or even open fires to heat their 

homes. In addition to posing a potential fire hazard, these 

practices can lead to the accumulation of dangerous carbon 

monoxide fumes, which are as deadly as fire.

Examples

Recent examples of heating fires:

October 2006: One man was hospitalized and a mobile 

home was destroyed in a fire that began in the mobile 

home’s hallway near the furnace. The local fire chief 

noted that the fire appeared to be accidental and due to 

a sudden cold snap early in the season. The resident was 

in bed, asleep, at the time of the fire.11

February 2005: Firefighters were called to a working 

chimney fire with embers coming from the chimney and 

smoke showing from the masonry. It was determined 

that the fire may have extended between the stove pipe 

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and the inside of the chimney. Firefighters on the exterior 

worked on containing the chimney fire while the interior 

crews checked for any extensions and hidden fires.12

October 2004: An electric space heater placed too close 

to a mattress caused a fire that killed a 65-year-old man. 

Arriving at 12:59 a.m., firefighters found a small fire 

involving a futon mattress. They brought it under control in less than 5 minutes, according to fire officials. 

The victim had been sleeping in the trailer when the 

fire broke out.13

December 2002: Investigators from the State Fire Marshal's Office say an unlined chimney was the cause of 

a predawn house fire that took the life of a 47-year-old 

man. Firefighters noted that the unlined chimney had 

eroded over the years and the heat from a wood-burning stove appeared to have ignited the fire.14

Conclusion

While declining in numbers, heating fires in residential 

buildings continue to occur. Many such fires can be prevented through proper maintenance and proper use of heating equipment. With the large percentage of chimney fires 

currently reported in NFIRS, most occurring due to lack 

of proper cleaning, the importance of proper maintenance 

cannot be overstated. Both furnaces and chimneys should 

be professionally inspected annually and cleaned as necessary. Chimney tar (creosote) build-up is a common cause of 

chimney fires.

Other areas in which homeowners can help prevent heating 

fires:

Make sure wood stoves are properly installed, away 

from combustible surfaces, have the proper floor support, and adequate ventilation.

Make sure your space heaters and portable heaters have 

an emergency tip-over shutoff in case they tip over. 

Never refill a fueled-powered space heater while it is 

operating or still hot. Refuel outside, away from the 

house. 

Use a glass or metal screen in front of your fireplace to 

prevent sparks igniting nearby carpets or furniture. 

Never use the range or oven to heat your home.

To request additional information or comment on this 

report, visit http://www.usfa.dhs.gov/applications/feedback/

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TFRS Volume 6, Issue 3 / Heating Fires in Residential Buildings Page 7

Notes:

1 In NFIRS 5.0, a structure is a constructed item, of which a building is one type. The term “residential structure” commonly refers 

to buildings where people live. The definition of a residential 

structure fire has, therefore, changed to include only those fires 

where the NFIRS 5.0 structure type is 1 or 2 (enclosed building 

and fixed portable or mobile structure) with a residential property use. Such fires are referred to as “residential buildings” to 

distinguish these buildings from other structures on residential 

properties that may include fences, sheds, and other nonhabitable structures. As the confined fire incidents may not have the 

structure type noted, confined fires without a structure type specified are assumed to be buildings. Those that occur on residential 

properties are then assumed to be residential buildings. Only confined trash fires coded as enclosed building and fixed portable or 

mobile structure are included in this definition; all other confined 

trash fires are excluded.

2National estimates are based on native version 5.0 data 2002–04 

from the NFIRS, and national residential structure fire loss estimates from the National Fire Protection Association’s (NFPA) 

Annual Survey of fire loss. Fires are rounded to the nearest 100, 

deaths to the nearest 5, injuries to the nearest 25, and loss to nearest $M.

3 For purposes of this analysis, residential building heating fires are 

defined as those residential buildings (defined above) for which 

the cause of the fire was determined to be heating. However, for 

the confined fire portion of residential building fires, only those 

with incident types 114 and 116 were included; all other confined fire types were excluded.

4NFIRS 5.0 contains both converted NFIRS 4.1 data and native 

NFIRS 5.0 data. This topical report includes only native 5.0 data.

5Non-confined fires are those fires in the 110 to 112 and 120 to 

123 incident type series. Incident type 112 was excluded from 

this analysis of residential building fires, however, as incident type 

112 is defined as “fires in a structure other than a building.”

6Confined fires are limited to those fires with incident types 113 

to 118, the confined structure fire incident range. Confined heating fires, however, are limited to incident types 114 and 116.

7 Fire in the United States 1983–1990, Eighth Edition, U.S. Fire Administration, Federal Emergency Management Agency, 1991. This 

publication uses “residential structure” fires as the basis for 

residential heating fires. In NFIRS 5.0 data, residential buildings 

comprise 90% of residential structures. A rough equivalent for the 

1983 estimate of residential building heating fires then might be 

180,000 fires rather than the reported 200,000 residential structure heating fires.

8National estimate, 2004 data.

9

The NFIRS definitions of housing types do not exactly coincide 

with the U.S. Census Bureau definitions, as there is no Census 

equivalent for two-family dwellings. NFIRS includes most manufactured homes (the U.S. Census refers to this group as “mobile 

homes.”) as a one- or two-family home. Single-family detached 

homes make up 60% of the U.S. housing stock, mobile homes 

make up 7.6%. For comparison purposes, these two Census 

groups are used as one- and two-family dwellings. Singlefamily attached homes (row houses and townhouses) are considered multifamily dwellings in NFIRS, and are included in 

that category for this comparison. Detailed definitions of NFIRS 

property use categories can be found in the National Fire Incident 

Reporting System 5.0 Complete Reference Guide, January 2006, at http://

www.nfirs.fema.gov/_download/nfirs50crg2006_0328.pdf U.S. 

Census housing information can be found at http://www.census.

gov/hhes/www/housing/census/historic/units.html

10These confined heating fires are coded as incident types 114 

or 116. The full definitions of these incident types can be found 

in the National Fire Incident Reporting System 5.0 Complete Reference Guide, 

January 2006, at http://www.nfirs.fema.gov/_download/

nfirs50crg2006_0328.pdf

11 “Fire Officials Suspect Cold Weather Prompted Furnace Fire,” 

AccessNorthGa.com, October 16, 2006, http://www.accessnorthga.com/news/hall/newfullstory.asp?ID=107939

12 “Virginia Firefighters Extinguish Chimney Fire,” updated February 28, 2005, http://cms.firehouse.com/content/article/article.

jsp?sectionId=45&id=39734 

13 “Space Heater Causes Fatal Fire In South San Jose,” Bay City 

News, October 12, 2004, http://abclocal.go.com/kgo/story?secti

on=News&id=2248427&ft=print

14 “Unlined Chimney Blamed for Fatal Fire,” December 11, 2002, 

http://www.deaftoday.com/news/archives/000818.html

Related Topics:

For additional tips on how to prevent heating fires in 

your home, please see: www.usfa.dhs.gov/subjects/fireprev/qr/

materials/factsheets/ffwfmc-5.shtm and www.usfa.dhs.gov/safety/

tips/winter.shtm