I have a Payne Furnace model number PG8DAA024050 giving me a 31 code. Two months ago I had a 33 and changed the Flame roll out switch. This is used in are mother-in-law apartment so it's not used all that much, but do need to keep that part of the house warm. There are a list of things like, defective inducer motor or start capacitor, and others. Here is what it does, The blower motor comes on for about 90 seconds then the inducer motor kicks on for a few seconds then the code 31 starts flashing. The furnace never attempts to light. I never see the igniters glow to ignite the gas and never here gas flow. I will appreciate any help!