Originally Posted by hbn7hj
Don’t give him any flack, he was good enough to tell us the resolution!
Propane valve function is difficult to check for. Without removal of the furnace you can’t tell whether the valve wouldn’t open or didn’t get the signal.
Exactly what I was thinking, also. When we had our furnace problem I checked to see it had power and a signal from the thermostat at the input harness and it did so I knew I needed to pull the furnace to see what was going on.
At least in our 07 that has the furnace up front, pulling it is only about 10 minutes or less and 5 more to get the covers off. Ours was a bad board that wasn't turning anything on from the signal and it took only few minutes to determine that when it all is accessible to track the signals as they happen. You do need a 12 source to do it on the bench though, that is why I keep a small AGM battery around and use it a for a lot of things.