I am trying to troubleshoot what is causing my blower to run non stop (the condenser (outside unit) comes on only when cool is required). There is no issue with cooling the house. I read through all the posts related to similar issue from this forum, but my issue looks peculiar. I checked the thermostat, the fan is set to auto and the wirings look good. Upon testing the control board with a multimeter, the HI HEAT terminal is showing 120 volts even when the thermostats are off or removed. I checked the limit switches and they are showing 0 volts, so they are not tripped either.
For now, I have detached the wire from the HI-HEAT terminal (that goes from the terminal to blower) and the unit is tuning on and off along with the condenser unit (only when the cool is required). However, summer getting over, I want to get this fixed before the winter cold starts.
I think it is time to check with our experts on what is causing the HI HEAT terminal to request 120 volts which in turn is making the blower to run non stop.