I was called to a home to repair a Lennox heat pump that was not working properly. Upon arrival, I found that the unit was not producing any heat. I checked the system and found that the compressor was not running. I checked the power supply and found that it was working fine. I checked the thermostat and found that it was set to heat. I checked the air filter and found that it was dirty. I cleaned the air filter and the system started working again. I tested the system to make sure it was working properly and left the customer with a working heat pump.
