My Heat Pump is on Fire!

Every tech that works on heat pumps will eventually get a service call from a distressed customer who believes their heat pump is on fire because they saw smoke pouring out. Typically, they just happened to catch the end of a defrost cycle and saw steam rising out of the unit as the defrost cycle finishes. They can see that the outdoor fan is no longer turning, yet they can hear the compressor still running. They may also hear loud compressor noises or the refrigerant whoosh as the system reverses at the conclusion of the defrost cycle. If they are near a register inside, they will most likely notice that the air is not very warm. All of this panics the customer into believing something terrible is wrong with their system. Simply telling them that this is all normal may sound like you are not interested in their problem. Or worse, you are hoping they will forget about the problem long enough for the warranty to expire. You should check the unit to see that it operates normally in first stage heat, second stage heat, emergency heat, and defrost. Then, explain the purpose of the defrost cycle. You probably don’t have time to completely explain heat pumps and the defrost cycle, but you can explain that ice buildup occurs as the unit operates and that it must be removed to keep the system operating efficiently. Once they understand that the defrost cycle is intended to heat up the coils to remove frost and ice, it is easy to see why you would not want the fan running while trying to heat up the coils. Heating the outdoor coil also explains the “smoke,” which if course is really steam created as the coil heats up. Finally, the loud compressor and whoosh noises simply signal that the defrost cycle is over as the reversing valve shifts. Taking the time to thoroughly check their system shows the customer that you are indeed interested in their concerns. Taking the time to explain what is happening will help reassure them and save you time down the road. Next time they will know what they are seeing.