Been working on a York furnace. The call was about no heat and high limit being tripped. Found there was an ecm blower motor and it would start to spin get a few rotations at a decent speed then stop, and keep doing this. Verified proper voltage and then checked the motor with an ecm tester and it kept doing it so I condemned the motor. Get out there today and the new motor does the same thing when I plugged it in to check it before installing. So I looked into the boards more and noticed that the board where the low voltage wiring went back too had a light with CFM above it and it would flash green and the light would intermittently die out and that’s when the motor would just stop. And the light would flash on and off and that’s when the motor would ramp up and down as if it was losing connection. Also noticed this board had some Smokey spots. So now I am wondering if the board is shot too. Any thoughts? I have also found out this customer has had the unit for 10 years and only changed the filter a few times and never got maintenances.

Posted by Austinproe at 2025-01-25 19:27:02 UTC