Expert: kdgrayson@gmail.com - 11/3/2009

Question
i have A 80 pecent payne furance with a code 22 i replaced gas valve and gas presure was 12 iwc at the valve also when you disconnect the thermistate wires from board the vent moter will run a few seconds and quit then start again i suspect a board problem what do u think

Answer
I have seen this many times and its a purge , according to all I have found, uless the board isnt working now , dont worry, with boards , essentially if your safeties and limits etc are all good?  is if you have power in and nothing out ,  its bad!

As for the water column measurement, I am assuming your talking propane!!
not nat gas??  cause if you have 12 with gas , thats wrong!  11.5  for propane   3.5 nat gas