My propane furnace will not light. The fan runs but the gas will not ignite unless I physically close an electronic switch. If I close the switch in a few seconds the gas ignites but most times it doesn't continue to burn. It is a Heil Furnace and it is about twelve years old.

If I shut the whole furnace off and turn it back on and do the same as above for a second time the gas lights and the furnace will run to reach the desired temperature in the house. It will continue to start and stop for when needed for the next few hours but eventually it will need a kick start again.

I assume that switch is either dirty and bad. I think I had it changed about two years ago because the same problem was happening.

How would I attempt to clean the switch? Do I use a computer air cleaner that blows forced ait over the connections to get rid of any dust? Is there a liquid cleaner I should try or do aI need to replace the switch?

Doug

What switch are you talking about? Is this the end switch on the draft booster motor also know as the combustion air motor?