Goodman Furnace Power Ventor Fan Runs Continuously w/o Thermostat On

Hello,

I have a Goodman GMP050-3 Gas Furnace. I put a new control board in and now the Power Ventilator (not the blower) fan runs constantly without the Thermostat turned on. Nothing else turns on and the unit won't ignite. The only way to turn off the Ventilator fan is to release the door switch. Every thing on the unit appears to be working, including the gas valve, rollout switches, flame sensor and limit switch. What could the issue be?

Thanks for your help,

Vic

 

mine does this exact same thing, only when I unplug the limit switch. so check for open circuit maybe?

different furnace though but might help...

dealing with an issue myself.

 

peels,

I'm guessing you have a furnace made by Carrier, which includes brand names Bryant, Payne, Day and Night.

A lot of those furnaces will turn on the blower motor that circulates air around the house when the limit switch opens or is disconnected.

But that's a different issue from what is described in the opening post.


I don't have an explanation for that issue. Could be an incorrect installation of the circuit board, a change in how the circuit board should be connected, or a defective circuit board. Does the new circuit board have the identical part number as the old one? If not, I'd read any installation instructions packed with the circuit board VERY CAREFULLY for any changes.


It's quite common for manufacturers to change circuit boards and other parts in ways that require modifications in how they are installed. Sometimes manufacturers provide instructions on that, and other times it's up to the repairman to figure out how to make the part work properly.

Fun, eh?