U.S. Fire Administration

TOPICAL FIRE RESEARCH SERIES

Volume 1, Issue 9

January 2001 (Rev. December 2001)

Heating Fires in Residential Structures

FINDINGS

S Since 1984, heating fires have decreased fourfold, primarily because

the 1980s surge in the use of space heaters and wood burning has

abated.

S Heating fires are the leading cause of fires in rural areas of the country. They represent the second leading cause of all residential fires

(behind cooking fires).

S More than half of residential heating fires are due to mechanical failure. In one- and two-family residences, one-third of heating fires results from improper maintenance of heating equipment.

Each year in the United States, an average of 48,300 heating fires occur in residential structures, which are responsible for 320 civilian fire deaths, 1,300 injuries, and

$450.8 million in property loss.

1 This topical report examines the causes and characteristics of residential heating fires.

Data from the National Fire Incident Reporting System (NFIRS) (1996–1998) show

losses from heating fires are higher than those averaged across all fires (Figure 1). Heating is second only to cooking as the leading cause of residential structure fires. 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 in large part stimulated by an

energy shortage and environmental concerns. The overall number of fires in the nation

has decreased over the last 15 years, but while other categories of fires (e.g., cooking)

have held steady or declined slightly, the incidence of heating fires has decreased dramatically over the last decade (Figure 2). In 1983, there were nearly 200,000 such fires;

2 by

1998 that number had fallen to approximately 50,000.3

Figure 1. Loss Measures in Residential Structures

(3-year average (1996–98) from NFIRS data)

ALL RESIDENTIAL

FIRES

RESIDENTIAL

MEASURE HEATING FIRES

Dollar Loss/Fire

Injuries/1,000 Fires

Fatalities/1,000 Fires

$11,271

48.0

7.7

$9,179

28.9

5.7
Figure 2. 15-Year National Trend in

Heating Fires in Residential Structures

(NFIRS data and NFPA Annual Surveys, 1984–98)

0

50

100

150

200

84 85 86 87 88 89 90 91 92 93 94 95 96 97 98

Fires (thousands)

EQUIPMENT INVOLVED IN HEATING FIRES

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, chimneys, and water heaters. Figure 3 illustrates the leading types of equipment involved in

these fires.

Figure 3. Leading Equipment Involved in Heating Fires

(residential structures, adjusted %, 3-year average (1996–98) from NFIRS data)

0 5 10 15 20 25 30

Fixed Local Heating Unit

Central Heating Unit

Chimney

Water Heater

Indoor Fireplace

Portable Heating Unit

Percent
TIME OF YEAR

Figure 4 shows the pattern of heating fires throughout a year. As would be expected,

the number of heating fires increases during the late fall and winter months (November

through March) when people increase their use of central heating systems, portable heaters, and fireplaces. The peak months for residential heating fires are January and February, with a decline through the remainder of the winter season. Despite the increased use

of heating equipment, heating fires still remain the second leading cause (behind cooking) of residential structure fires in the fall and winter months.

0

25

50

75

100

125

150

175

200 7/1

7/157/298/128/26

9/9

9/2310/7

10/21

11/4

11/18

12/2

12/1612/30

1/131/272/102/243/103/24

4/7

4/21

5/5

5/19

6/2

6/166/30

Incidents

Figure 4. Heating Fires

(residential structures, adjusted %, 3-year average (1996–98)

from NFIRS data)

The equipment involved in heating fires varies by area of the country. In the South,

chimneys cause more heating fires than central heating systems, while the opposite is true

in the North. Given climatic differences, fewer southern homes may have central heating

systems than those in the North, and southerners are more likely to rely on fireplaces and

other heat sources.

4
WHAT IS IGNITED?

The leading forms of material ignited in heating fires are rubbish and other trash,

structural framing, electrical wire, and fuel (Figure 5). There are variations, however,

depending on the particular heating equipment involved. For example, fires involving

portable heaters (the subject of another topical report) are more likely to involve bedding

than other heating sources; more than half of chimney fires involve the ignition of rubbish or trash.

PERCENT

Resin/Tar

Sawn Wood

Combustible Liquids

Fabric

28

18

6

8

28

13

10

8

Figure 5. Material Ignited in Heating Fires

(residential structures, adjusted %, 3-year average (1996–98)

from NFIRS data)

TYPE FORM PERCENT

Rubbish/Trash

Structural Framing

Fuel

Electrical Wire

The leading types of materials first ignited are resin/tar, sawn wood, fabric, and combustible liquids such as kerosene, fuel oil, and diesel fuel. Again, there are variations

depending on the type of heating equipment involved in the fire. For example, the leading type of material ignited in fires involving fireplaces is sawn wood. But the leading

type of material ignited in chimney fires is resin/tar, known as creosote, which is a natural byproduct of burning wood. (Anecdotal evidence suggests that firefighters may report

to NFIRS that creosote in chimneys is caused by waste/rubbish, thereby explaining the

prevalence waste/rubbish as the type of material ignited.)
- - -

-

WHAT IGNITES THE FIRE?

As illustrated by Figure 6, 58% of all heating fires are attributed to some form of

mechanical failure. Of those fires caused by some kind of mechanical failure, 32% are

caused specifically by improperly maintained equipment. Combustibles placed too close

to a heating source cause an additional 13% of heating fires.

0

25

50

75

Percent

Figure 6. Leading Ignition Factors

in Residential Heating Fires

(residential structures, adjusted %, 3-year average (1996–98)

from NFIRS data)

Too Close to

Combustibles

Lack of

Maintenance

Mechanical

Failure

Although nearly half of all heating fires involves some kind of mechanical failure,

the reason for that failure varies depending on the type of residential property involved in

the fire. In one - and two -family residences, nearly one -third of heating fires is due to

improper maintenance. In contrast, only 10% of heating fires in apartments results from a

lack of proper maintenance; apartment fires are more likely to be caused by a short

circuit or part failure.

5 This variance may be because apartment complexes generally

contract out heating system maintenance or assign that responsibility to in -house facilities maintenance personnel. Homeowners, on the other hand, are entirely responsible for

either undertaking this maintenance or ensuring it is done by others.

CIVILIAN FATALITIES

Heating is the third leading cause of civilian fire deaths, following smoking and

arson. When analyzed further, however, heating fires in residential structures are the

leading cause of fire deaths in rural areas and are not a leading cause of fatalities in

urban areas. This disparity may be due the to prevalence of central heating systems and

apartments in urban areas.

6
-

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. In one such fire, a gas stove was turned on to help heat a Baltimore home. The

flames from the burners ignited items in the kitchen, sparking a fire that killed four members of a family, including a 5 -year old child.7 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.

NOTES

1. National estimates are based on National Fire Incident Reporting System data (1996–1998) and the

National Fire Protection Association’s (NFPA) annual survey, Fire Loss in the United States.

2. Fire in the United States 1983–1990, Eighth Edition, U.S. Fire Administration, Federal Emergency

Management Agency, 1991.

3. NFIRS, 1998 data.

4. The Rural Fire Problem in the Untied States, U.S. Fire Administration, Federal Emergency Management Agency, 1998.

5. NFIRS analysis, 1998 data.

6. Profile of the Urban Fire Problem in the United States, U.S. Fire Administration, Federal Emergency

Management Agency, 1999.

7. “Family Tragedy, Four Killed in Fire,” The Baltimore Sun, January 20, 1997.

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