I have a Goodman Propane fired Furnace - Model number GMH950904CXAC (Only a furnace NO air cond.) (used the factory switch over kit) and are having problems keeping the furnace running. If it wants to start it may start the 5th, maybe the 10th, or maybe not at all. I have looked for codes and all I get is the same SOLID RED light. I have cleaned the flame sensor a dozen times and that so that is not the problem.
IF I AM LUCKY and the furnace does fire up it runs smoothly and does a fine job of heating. BUT the big thing is IF IT FIRES UP!
Is there a way to test the flame sensor? Can you by-pass the flame sensor? OR should I be looking at something else? Thanks in advance. [email protected]
Ralph

You test a flame sensor by reading the micro amps. A flame sensor is just a metal rod cased in ceramic. Not much to go wrong except if the rod or ceramic is broke. Make sure you have a good ground wire connection for the gas valve(no good ground no flame sensing). Make sure the burner are clean and the flame is hitting the sensor. I can see a flame sensor wire go bad before the sensor its self.

Thanks ever so much. I will check that and go from there. -19 last night so going to have to figure this out soon.
Ralph