My home ac unit works only when fan is set to on, why?
I have a Goodman rooftop package unit. The problem I have is only one. The A/C only works when the fan is set to ON and not on Auto. When set to AUTO, I hear the A/C compressor humming for a few seconds then always immediately stops humming, and the fan never turns on. When I set the thermostat to Heat and set to FAN AUTO, the fan turns on after a few seconds when I call for heat. Why doesn't my fan turn on when I call for A/C?
sounds like the relay in the t-stat is sticking or another problem in the t-stat. IF you set the fan to on and the blower runs, then I would start by replacing the stat. If the blower does not run when you set fan to auto then it could be in the control board of the package unit