Space Heater Fire Cause

Recently, we were asked to investigate a fire involving a newly purchased space heater. Space heaters tend to be small heating appliances meant to heat “small” spaces inside a home or other building. In this particular case, the heater was intended for use with propane gas and rated with a capacity of 30,000 BTU/hr. The homeowner had purchased the heater from a local Home Depot store and installed the heater himself. The installation amounted to connecting the heater to a gas supply line. After approximately three days use, a fire occurred. Luckily, the fire was quickly extinguished with minimal burn damage to the floor and smoke damage throughout the remainder of the home. Upon visual examination of the gas line connection, it was noted that the shutoff valve had been attached to the heater gas line fitting. The proper position for the shut off valve was in the gas supply line from the home at the point where the line was accessed above the floor. The outlet of the valve is then supposed to be connected to that part of the gas line that is connected to the heater. However, the main problem was found to have been in the connection of the valve to the heater fitting. The shut off valve appeared to have been cross-threaded onto the fitting. The pipe joint compound used to seal the threaded connection was also scorched and was indicative as well as a confirmation of a gas leak at that point. In should be noted that since propane is heavier than air, an accumulation around the heater while it was in operation would have ignited, which is what actually happened. The photographs below show how the shut off valve was misaligned with the heater fitting and the resulting damage to the heater.

Christmas and Safety

Christmas is fast approaching and so is winter. Although it is cold in many parts of the country not everyone has begun using their heating appliances on a regular basis. Instead, every year people resort to using small free-standing heaters to warm a room. From a fire investigation standpoint, I’ve already encountered two instances where small space heaters have been suspected as being the cause of a fire. Small space heaters are not necessarily defective and inherently dangerous if used properly. If the instructions say to keep the unit a certain distance away from combustible material, then, it is imperative that the minimum distance be maintained. The trouble is that consumers have a tendency to forget about that distance. Even more troubling is the fact that consumers will operate a small heater all night and unattended when that is clearly not the manufacturer’s intention. Remember that warm spot on the corner of the sofa that was created when the heater was turned on? After several hours, that warm spot can turn into a hot spot and then a point of ignition; all because the heater should not have been left on. That scenario prompts a question: can the heater be left on all night if the heater is sufficiently far away from all combustible material? The short answer is no. Anything that could knock the heater over might cause a fire. Most small heaters are equipped with a tip switch that turns the heater off in the event that the unit is tipped over. However, even though the power is off, that doesn’t mean that whatever the heater is resting on won’t ignite because of the residual heat emitted by the heater until it cools. The same rules apply to the use of kerosene heaters. In the case of kerosene heaters however, there is a steady production of carbon monoxide as the kerosene is burned. People with breathing difficulties can be severely affected. If a unit is allowed to burn all night, the risk that occurs is that there will come a point where the kerosene level will be low enough to produce soot instead of heat. So, in either case, whether using an electric or kerosene heater, it is best not leave them on and unattended during the night.

Hopefully, this reminder will help someone avoid a disastrous holiday season.

Merry Christmas and Happy New Year everyone!

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