Thermostat Problems

• Although your propane furnace may be ready to warm the home, it cannot do its job without the thermostat telling it to start. The thermostat is the device you use to set the desired temperature so that it remains comfortable throughout the day and night. The thermostat problem can be simple human error. Ensure you have the desired temperature set high enough that it exceeds the current room temperature or the furnace will not start up. In addition, the selector switch should be set to "heat." Ensure that it hasn't been accidentally bumped into the "Off" or "Cool" positions. If these simple solutions do not apply, then there may be a wiring problem inside the thermostat causing your unit not to come on.
  
  

Pilot Light

• A propane furnace works by releasing the propane fuel into a combustion chamber where it is lit to begin warming the air to be blown into the house through the ducts. If the propane does not ignite, the fans are simply blowing the room temperature air mixed with gas through the house. If you smell gas, this could be the case. It probably means your pilot light is not lit.
  
  If you have a system with a standing pilot light, there should be a small blue flame in the combustion chamber that ignites the propane whenever it is released. This flame can blow out and cause this nonheating problem. If you smell gas or otherwise notice the pilot light is out, turn the system off, open the windows to vent the house of fumes and relight the pilot before turning the heat back on. If you are not comfortable with this process, call a professional to do it for you. Local gas companies will often come and light your pilot for you.
  
  

Fuel Supply

• Unlike natural gas and electricity, which is piped into your home from a central source, propane is typically bought in limited quantities. It is stored in a tank on your property that will eventually run empty with use. If your furnace is not heating, there is no gas smell and the pilot light is off, it is very possible you have simply run out of propane. Plan ahead to have propane delivered before your system gets low on fuel to prevent cold nights in the home.
  
  

Fans

• If the problem with your propane furnace is with the fan that circulates the heat through your home, there could be a few different problems. Faulty wiring or a lack of electricity are likely problems. If wiring is the cause, the system needs to be turned off and a qualified technician needs to have a look to determine the exact problem for repairs. A simpler problem could be that a circuit breaker has tripped, cutting off power to the furnace. Since it is a propane system, it could continue to heat but the lack of power wouldn't allow the heat to blow out the vents.