I am working on an American Standard lp gas furnace, model ADX060C936CO (hot surface ignitor). The only thing that seemed to respond on a call for heat was the inducer fan (ignitor did not heat). I found the diagnostic light giving 6 flashes, which indicates a ground or polarity problem. Polarity was correct, so I dug in and found that one of the leads to the HSI had been allowed to contact the burner, and had of course melted. I figured okay, that's my grounding problem. I repaired that, and sure enough, next test I got a glowing ignitor. However, no ignition, and light continues 6 flashes. Tested the pressure switch, got 24 volts going through the switch. I adjusted the thermostat so that there was no call for heat, and nothing changed. I powered off the unit for a few minutes, and powered on with no call for heat - immediately, glowing ignitor. I have a suspicion that the short at the ignitor could have damaged the IFC board. Discuss?