I am a homeowner with two nearly identical units, one for 1st floor, one for 2nd floor (Goodman GMS30703ANA). Both units are about 7 years old.
Our 1st floor unit (3 burners) was intermittently failing to ignite (startup sequence made it to the ignitor glowing hot, then failure). Always the same - call for heat, inducer start, ignitor light, no flame.
Because our other unit has identical parts, I started - Pressure switch first. Switch worked fine on the other unit. "New" switch installed into the problem unit, and then the problem on the "bad" unit - now it will not even start up the inducer. It gets power to the circuit board (red LED light steady red), I can turn on the house fan, but no startup sequence whatsoever (unlike previously when it failed to generate a flame).
So, what are the possible culprits for the original problem followed by the new problem? Which would be the most likely culprit?
I - "circuit board". So I swapped circuit boards between the two units (they were identical). Nothing different on the "bad" side; "good" side works fine with the swapped board.
Then, I - maybe the ignitor itself. So I swapped that. - works on "good" side; nothing different on the "bad" side.
My next guess would be ground wire (inspected it, and nothing obvious wrong with it). I plan to replace it, just in case, but I am ready to call in reinforcements!
I cannot find my multimeter to test anything; decided just to swap potential problems to see if I could hit pay dirt. I've had enough of that and would appreciate helpful suggestions.
If it does not even start the inducer now, while it did previously, what would make sense to explain that new condition?