Originally Posted by billkateposs
Thank you Martin. We do not know where to begin to find out what is not working with our furnace.
After you have checked structural integrity of the combustion chamber (corrosion and gaskets) and for gas flow and leaks
, there are two things that may prevent your furnace to ignite:
1- There is a small metal rod sticking just under the pilot that is meant to detect if the pilot is lit. That rod must be heated in order to leave the gas flow to the burner. If the pilot is not burning, you don't want the gas to accumulate and cause a potential explosion. If you hold on the red button to allow the gas to flow, you are bypassing this safety to lit the pilot when it is cold. If that pilot safety is misplaced or defective, your furnace pilot will not remain lit after you release the pressure on the red button. Such safety device is standard on just any propane fridge
or furnace. Finding a compatible spare part is likely going to be challenging.
2- Once you have the pilot lit, there is a temperature sensor that controls the flow of gas onto the main burner. If that sensor is defective, the pilot will lit, but the main burner will not go on even if you turn the red button to the highest temperature setting.
By the way, if you have disconnected gas or not used the furnace for a long time, you may have to wait a couple of minutes for the gas to reach the pilot.