Hi one of the 2 Lennox THA090 rooftop compressors is not running even though we set the temperature really low. The office still feels warm. We opened the cover and confirmed that one of them is running and the other is not.
However the 2 PCB control boards all seem to indicate everything is fine, based on the LED blink pattern. Any clue? Thanks a lot!
How do we test if the compressor is really broken?
The unit is about 10 years old.