Hello all! I'm new here and would love some help.
I have a 2 year old Goodman Furnace - it's a 95% efficent model that has the variable speed fan and 2 stage burner. (not sure the model # offhand)
It's been a decent furnace, however last heating season I had issues with it heating - the igniter would not fire, so I hooked up a multimeter and found the igniter to be OK, but the main circuit board was bad from what I can tell. The place I bought the furnace from replaced the board at my cost.
The A/C has been working fine all summer, and tonight being cool we went to kick on the heat only to have it not work.
What will happen is when the call for heat comes in, the exhaust blower fan starts up for about 1 second then it shuts off and nothing else happens.
The red LED just blinks continously. There is a greed LED on the circuit board that blinks very faintly, and that's it.
I read on the schematic that if the LED is blinking cont. that means the 115V is reversed, so I hooked up the AC power leads the opposite way and tried it again, and what will happen is the exhaust blower kicks on for about 15-20 seconds (enough to get to full speed) and then it shuts down with no trys at a restart - only a cont. blinking red LED. the green one is blinking very faintly.
with the 115V AC hooked up backwards - that's when i get the longer run time on the exhaust blower, but I tested and I'm feeding the 115V to the neutral leg on the circuit board. With it wired properly (it did work last season, but it doesn't now) it will only run that exhaust blower for a very short time and nothing else happens - no igniter, fuel or main blower action...
Help? is my main circuit board fried again?
One other thing I noticed is there is a slight high pitched buzz/hum coming from the circuit board when the fan was being energized, even with the fan unplugged.
thanks for your help!