I have a Janitrol / Goodman GMP125-4 gas furnace. Two years ago we replaced the motor, capacitor and the venter blower assembly. Last year (Nov 2006) we replaced the thermostat with a Honeywell programmable thermostat and then followed that with replacing the original integrated circuit module with a new one. Right now - when the thermostat calls for heat, the venter blower turns on, followed the gas turning on but I don't see the igniter going on. After a three tries it shuts off then tries about 30 minutes later. The red LED on the integrated circuit module is a slow but constant blinking. According to the back of the blower door (lower) this means "improper polarity" and or "twinning fault." Any info will be appreciated.

sounds like you need a igniter,,,,kill the power to furnace at the breaker box,wait a few seconds and turn back on,it should start the sequence again,,,,1st the induction motor comes on,the igniter should come on next,then the gas valve open up,if the igniter doesn`t work the gas valve won`t open,,,,,,goodmans are pretty tuff on igniters,for some reason

Thank you - you are right on track. I shut off the power and removed the igniter assembly. It appeared to have arched over causing a short. It definitely needs to be replaced. I will also replace the flame sensor while I am at it. Again, thanks a lot.

I changed the igniter assembly and the flame sensor and everything is working great. It looks like the arch in the igniter assembly caused the constant blinking red LED / fault code.