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Common Causes of Electric Space Heater Fires & Methods of Prevention

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We all love staying warm in winter. We turn up the thermostat, burn logs in our fireplace; heat up the bed with an electric blanket, and sometimes use electric space heaters to keep the temperature cozy. When it comes to space heaters, it’s important to note any objects in close proximity and/or in contact with the heater that could cause a fire. In this paper, we examine common causes of electric space heater fires, discuss methods to prevent their occurrence, and review fire investigation and subrogation considerations to be aware of following a fire event.

A Leading Cause of Fires

According to the National Fire Protection Agency (NFPA), heating equipment is a leading cause of fires in U.S. homes. Local fire departments have responded to an average of 52,050 fires involving heating equipment each year from 2012-2016, accounting for 15% of all reported home fires during this time. As a result of these fires, there were 490 civilian deaths, 1,400 civilian injuries, and one billion dollars in direct property damage.

The Consumer Product Safety Commission reports that approximately 1,200 fires a year are caused by portable electric space heaters. Although electric space heaters are generally more expensive to operate than combustion space heaters, they are the only unvented space heaters that are safe to operate inside your home due to the lack of carbon monoxide emissions.

Types of Electric Space Heaters & How They Cause Fires

There are four basic types of electric space heaters:

  • Ceramic heaters, which contain a heating element that reaches a high temperature and the element is usually packaged inside a glass envelope.
  • Convection heaters, which contain a heating element that operates by air movement as the air circulates through the body of the appliance and across the heating element.
  • Fan heaters, sometimes called a forced convection heater, which is a type of convection heater that includes an electric fan to speed up the airflow, usually allowing for increased heat production and distribution.
  • Oil heaters, which are another type of convection heater where the casing of the heater is filled with oil that is used as a heat reservoir providing more even heating.

To understand how space heaters cause fires, it’s important to know the basic dangers of the appliance. The first danger is the amount of current that is drawn during use. Most electric heaters are rated at 1500 watts which equates to approximately 12.5 amps. This amperage is well within the safe zone of operation in your home; provided the heater, power cord, receptacle, and electrical wiring are all in good working order, and that only one heater is used per electrical circuit. A defect in any of these crucial components can lead to a failure that may result in a fire.

A common problem associated with portable electric heaters is the use of electrical extension cords. Typically, recommendations by the manufacturer state that the electrical space heater be connected directly into an electrical receptacle. The space heater should never be connected to an electrical extension cord or an electrical power strip.

The second most common fire hazard associated with portable electric heaters is their proximity to common combustibles. Most portable heaters warn consumers to maintain a minimum of three feet of clearance from all combustibles. Many newer space heaters have safety features that will eliminate the heat or shut the appliance off if the space heater overheats or falls. Most, however, can’t detect if the objects around them are overheating or are in danger of ignition.

Figure 1
Figure 1

How Space Heaters Are Regulated

Space heaters are tested by organizations like Underwriters Laboratories (UL) and Canadian Standards Association (CSA). For example, a UL listed portable electric heater has to pass a tip-over test that simulates the most severe tip over orientation. The U.S. Consumer Safety Protection Commission (CPSC) helps reduce space heater risks by developing voluntary standards, issuing and enforcing standards, and banning unsafe consumer products. The CPSC also has a current list of recalled space heaters to protect consumers. Space heaters are also covered under the International Fire Code and National Fire Protection Association (NFPA) codes.

The International Code Council (ICC) covers space heaters under the International Fire Code, Section 605.10.1-4. The code lists under what occupancies space heaters can be used, it specifies that only listed and labeled portable space heaters can be used, and it states that they should be plugged into an approved receptacle. While many organizations note to avoid using an extension cord with space heaters, the 2018 ICC Fire Code Section 605.10.3 unequivocally states:

605.10.3 Extension cords. Portable electric space heaters shall not be plugged into extension cords.

In the 2018 ICC Fire Code 605.10.4, the code discusses prohibited spaces for space heaters, such as being operated within three feet of any combustible materials and only in locations for which they are listed.

One of the areas addressed in NFPA 1 - 2018, Section 11.5.3 covers space heaters used in offices. Some employees place heaters under their desk. While this may keep them from tipping over, they can also be forgotten and left on after workers leave for the day. The areas under a desk can also contain combustible materials in close proximity to the space heater, such as plastic waste receptacles which are significant fire risks. In addition, it is nearly impossible to maintain three feet of clearance under a desk.

NFPA 1 - 2018, Section 11.5 requires space heaters to be plugged directly into an outlet due to the amount of current drawn to operate them. Extension cords should not be used to plug in an electric space heater. The Authority Having Jurisdiction (AHJ) can prohibit the use of space heaters, based on their past inspection findings that violate this requirement.

Space Heater Recalls

While most space heater fires are caused by proximity to combustibles, there are instances where space heaters can overheat and cause the units to melt, then ignite nearby available materials. Below are examples of space heaters that have been recalled by the U.S. Consumer Product Safety Commission at

Figure 2
Figure 2

Twin-Star Duraflame DFS-220-RED | Photo Credit to

Twin Star recalled 31,000 Duraflame heaters that were overheating, then melting, then potentially igniting nearby materials. There were 32 reports of heaters burning or melting.
Figure 3
Figure 3

Home Depot Soleil Portable Heater | Photo Credit to

Home Depot recalled 103,000 portable fan heaters due to the potential for the plastic housing to melt and catch fire. There were 464 reports of the fans melting.
Figure 4
Figure 4

H.E. Industrial - Profusion Heat HA-22-48M | Photo Credit to

H.E. Industrial recalls 8,500 electric garage heaters due to the potential of the heating element overheating and causing a fire hazard.
Figure 5
Figure 5

Dyson Hot and Dyson Hot+Cool (AM04 and AMO5) | Photo Credit to

Dyson recalled 338,000 bladeless portable heaters in the U.S. and 43,000 in Canada due to a potential short that could cause the unit to overheat and cause a fire. There have been 82 incidents of units short-circuiting and overheating.

Fire Investigation & Subrogation Considerations: What to Be Aware of Following a Fire Event

The fire site, whenever possible, should be secured if an electric space heater is believed to be a potential cause of the fire. This will allow the forensic expert to properly investigate origin and cause, as well as subrogation potential. The scene should be documented with photos and/or videos as soon as possible before spoliation occurs. If the site has been disturbed, the space heater and any and all parts should be procured. The chain of custody should be protected with all transfers and secure locations documented in writing. The electric space heater should be stored in a secure location until it can be properly examined by the forensic expert, the manufacturer, and any other interested parties.

Space Heaters: Guidelines for Safe Use

Fortunately, there are simple safety guidelines that help greatly reduce the chance of a fire caused by a portable electric heater when properly followed. The following safety tips are outlined by the Consumer Product Safety Commission (CPSC) and most of these tips are also posted on new packaging when an electric heater is purchased.

  • Never operate a heater you suspect is damaged.
  • Before use, inspect the heater, power cord, and plug for damage.
  • Follow all operation and maintenance instructions.
  • Visit or to see if your electric heater has been recalled.
  • Never leave the heater operating while unattended, or while you are sleeping.
  • Keep combustible materials such as beds, sofas, curtains, papers, and clothes at least three feet (0.9 m) from the front, top, sides, and rear of the heater.
  • Be sure the heater plug fits tightly into the wall receptacle. If not, do not use the outlet to power the heater. Poor electrical connections are another leading cause of fires.
  • During use, check frequently to determine if the heater plug or cord, wall outlet, or outlet faceplate is hot. If the plug, outlet, or outlet faceplate is hot, immediately discontinue use of the heater. Have a qualified electrician check and/or replace the plug or faulty wall outlet(s). If the cord is hot, disconnect the heater and have it inspected/repaired by an authorized repair technician.
  • Never power the heater with an extension cord or power strip.
  • Ensure that the heater is placed on a stable, level surface and located where it will not be knocked over.
  • When purchasing a heater, ensure that the space heater has been approved by Underwriters Laboratories (UL). A UL certified heater will have a safety certification label.
  • Never place the space heater power cord underneath rugs or carpeting. This can damage the power cord, causing it and nearby objects to burn.
  • To prevent electrical shocks and electrocutions, always keep electric space heaters away from water and NEVER touch an electric heater if you are wet.


While electric space heaters can help keep room temperatures warm, they can also be dangerous and cause fires. Space heaters should never be left unattended or used within three feet of any combustibles and should always be plugged directly into an outlet. While most new units have built-in safety features to help prevent fires, there are many older units still in use without those features.

In the event of a fire, the fire scene should be protected and secured to prevent spoliation of the scene before a qualified fire origin and cause investigator can inspect the site. If the electric space heater is determined to be the cause of a fire, the unit and any parts should be secured and protected. The chain of custody outlining handling of the space heater and all transfers should be documented in detail. The unit should be stored in a secure location until a qualified expert and the manufacturer can inspect and evaluate the space heater.


We wish to thank Marc Fennell, IAAI-CFI for his contributions to this article.


  • Richard Campbell (2018). NFPA’s “Home Fires Involving Heating Equipment”. Quincy, MA. National Fire Protection Association Research
  • International Code Council (2018). Fire (2018). Country Club Hills, IL: International Code Council Inc.
  • Underwriters Laboratories (2009). Electric Heaters – Tip-over Protection from Issue 1, 2009 The Code Authority Newsletter. Northbrook, IL. UL LLC.
  • U.S. Consumer Product Safety Commission (2013) – CPSC Safety Alert “Reducing Fire Hazards for Portable Electric Heaters”. Publication 098. Bethesda, MA.
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This publication is for educational and general information purposes only. It may contain errors and is provided as is. It is not intended as specific advice, legal, or otherwise. Opinions and views are not necessarily those of J.S. Held or its affiliates and it should not be presumed that J.S. Held subscribes to any particular method, interpretation, or analysis merely because it appears in this publication. We disclaim any representation and/or warranty regarding the accuracy, timeliness, quality, or applicability of any of the contents. You should not act, or fail to act, in reliance on this publication and we disclaim all liability in respect to such actions or failure to act. We assume no responsibility for information contained in this publication and disclaim all liability and damages in respect to such information. This publication is not a substitute for competent legal advice. The content herein may be updated or otherwise modified without notice.

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