I was called to a home to check on a broken air conditioner. Upon arrival, I found that the thermostat was set to heat and the air conditioner was running fine. I checked the air filter and found that it was dirty, so I cleaned it and replaced it. I also checked the condenser unit and found that it was not leaking any refrigerant. I tested the electrical connections and found that they were all good. I then tested the fan motor and found that it was working properly. Finally, I tested the compressor and found that it was working properly. I also checked the air handler and found that it was working properly. I then gave the customer a detailed explanation of what I had done and answered any questions they had.