I have a 2002? Goodman Gas Furnace, model:GMNT120-5
The blower (fan) runs constantly, even if the t-stat is off/heat/cool or is set to on/auto.
I pulled the cover and everything appears fine, nothing burnt or damaged, the cabnit is clean. Fuse is good, and the trouble shoot LED is on indicating normal operation(per the manual).
To rule out a short in the Green 24v wire I unhooked it and swapped out a with another and the fan still comes on.
Sitting in front of the control pannel with everything hooked up and power on.. I can press the door switch and the LED will light up and the cap will begin to energize, when the cap is energized the relay will trip and the fan will come on. If I unhook the green(fan) wire this doesn't happen.
I've changed the t-stat (wanted a new programable anyway, so that's ruled out also).
Also wanted to say that the heat does work, if I dial the t-stat above room temp and set the t-stat to heat, the burner lights and heats the house to temp, then shuts off(but the fan stays on).
At this point I'm guessing a new control board?
Thanks for any help.
Eric.