A 29 Year Old Heat Pump Revived with a Heat Pump Repair in Johnson City, TN

Received a call from a new customer on Hopper Road in Johnson City, TN stating that their heat pump was not cooling and they had tenants living in the home. Headed over to the home to look at the system in hopes of performing a heat pump repair. When I arrived, I looked at the indoor thermostat after introducing myself to the tenants. The tenant accidentally put the unit in heat mode, but it was not calling for heat because the set point was 70 degrees and it was 78 inside the home. He had meant to turn it off, but accidentally hit the button too many times. I put the thermostat in the off position. I went outside to the heat pump and it was running to my surprise. The compressor sounded awful. I felt the air being discharged and it was cold, I felt the large copper line entering the heat pump and it was hot, and the liquid line when I touched it, burned my fingertips. These symptoms told me that the heat pump was running in heat mode and it was 84 degrees outside. I went to pull the outdoor service disconnect to shut down high voltage power to the system and I heard the compressor stop running and the outdoor fan motor continued to run. I hadn't even had time to set my bag down yet.

I pulled the disconnect, set my bag down, I opened the cabinet, confirmed high voltage was off, and tested the compressor windings between Common & Run. I had no continuity which told me the compressor went out on thermal overload due to overheating. I checked the low voltage wires C & Y to confirm that I didn't have a call for the outdoor unit to be running and I had zero volts or no call to the outside. I looked at the high voltage contactor and noticed that the contacts were burnt and charred. I had no call at the contactor, so it should not have been pulled in allowing high voltage to pass through it. I grabbed a water hose and began cooling the compressor with water in hopes that I could get the compressor out of thermal overload. While I was spraying the compressor, I went ahead and cleaned up the debris from inside the unit. Finally, after almost 15 minutes of spraying water onto the compressor it had cooled enough that the compressor windings between Common & Run had closed. It was out of thermal overload! I continued to spray water on the compressor for a few more minutes to further cool it down. I washed through the outdoor coil from the inside to the outside in order to remove all of the dirt and debris from the coil fins. I checked the dual run capacitor which was not secured in the cabinet to make sure I had the correct microfarad readings. I secured the dual run capacitor to the cabinet with band iron and 2 screws. I folded the band iron down over one of the screws to help prevent accidental cuts by anyone in the cabinet in the future. I changed out the high voltage contactor. I marked the white wire as a hot with black electrical tape. The cabinet was very tight and I had no slack in the high voltage wires, so I was only able to wrap around the white wire a few times. I restored high voltage to the system and the unit was not starting now with no call from the thermostat, which was good news. I hooked up my amp clamp on my electrical meter to take an inrush amp reading on the compressor and fired the unit in cool mode. My inrush amps were ok, my running amps on the compressor and outdoor fan motor were ok as well. I performed a temperature split test between return and supply to confirm that the unit was producing ample split. The unit was operating again. If you need help with your HVAC system and you have a home inside of our service area in Northeast Tennessee, please feel free to reach out to Magnolia Services based out of Johnson City, TN. Stay safe out there and best wishes.

Location: Johnson City, TN