The furnace has been acting up for a year. I decided it’s time to spend the time to take it out of the motorhome and find out why it works sometimes and at other times not at all. Before we left for Yellowstone in the Spring of 2017 I took the fan cover off and cleaned the fan blades. Thought it might be an air flow problem even though it is not giving an air flow error code.
I used compressed air to blow off the blades. It fired up the first time, turned it off and it started the second time the electrode cycled, turned it off and it started the first time.
Got to Yellowstone and only started once, oh well.
After the ring is off the furnace slides out. Well slides out is a relative term. I still need to unhook the power, gas and 5 duct tubes. You get to the 5 duct tubes from inside the motorhome inside the kitchen cabinets. Took 2 1/2 hours to get the 5 duct tubes off the furnace, oh well I guess I have the time.
After getting the furnace out and on the work bench I notice the electrode is a bite corroded.
Cleaned everything up, reinstalled the furnace (less the ducting) and nothing, could not even hear the electrode fire. I had the furnace in and out 5 times the other day. I final decided to order a new PC board and ignition electrode.
Three days later (thanks to Amazon) I got the needed parts, furnace out again, two new parts installed. Furnace fired up on the first cycle. After I got all the ducting hook up to the furnace it will fire up on the second or first cycle. I say second or first cycle because the first time I start the furnace it usually fires up on the second cycle. After I power down the system it will fire up on the first ignition cycle. The original PC board was not giving an air flow error code however I have decided to change out the sail switch before we leave to go south.
Update: Thursday August 10, 2017
Yesterday I installed the new sail switch. Could not test the furnace until this morning, the furnace thermostat only goes to 90 degrees and it was 97 inside the coach. I checked it this morning and it fired up on the first cycle.