Heat Pump Problems | HVAC Heating & Cooling - Heat Pumps are very popular especially in the South where air source heat pumps are mostly favored over straight air conditioners with a gas furnace for heating. With a heat pump, one system can provide heating and cooling. Some people rely on a geothermal heat pump system or a water source heat pump. A geothermal heat pump extracts heat from the ground instead of the air like an air source heat pump works.
Heat Pump Problems
Air source heat pumps are cheaper to install than geothermal heat pump systems. However, geothermal heat pumps will save a lot of money over the life of the heat pump in operating costs.
Geothermal heat pumps are more efficient than air source heat pumps. There may be a time when your heat pump will begin giving you problems. We decided to post an article to help some people diagnose the heat pump problem. Remember to always be safe and do not go above your comfort level or skills. When in doubt call a professional. Some minor repairs can be done by someone with minimal skills. However, we always recommend you call an HVAC contractor to repair the problem. Especially the bigger problems that require specialized tools. Before you get started you may want to take a look at a few of our other articles.
“How Heat Pumps Work” , “Heat Pump Components” and “heat pump sequence of operation“. To solve heat pump problems you at least need to be familiar with a heat pump. Being familiar withy heat pump components will also help you.
Heat Pump Problems - Accumulator
One of the most problematic heat pump components that I often find wrong is the accumulator. An accumulator is a reservoir that allows liquid refrigerant to be stored and boiled off. It does this so liquid does not harm the compressor.
It protects the compressor in the winter. It is an essential component to prevent other problems with the compressor. The problem with all the accumulators is they are made out of steel. Accumulators are exposed to the environment and usually rust despite the best efforts of the manufacturer to paint and protect the accumulator from rusting.
Most accumulators will rust out on the bottom. The heat problem will start with a pin hole leak allowing refrigerant to leak out. Eventually, the heat pump stops working until refrigerant is added to the unit. The accumulator needs to be changed to eliminate the problem leak. This heat pump problem should be done by a qualified HVAC technician.
Heat Pump Problems - Defrost
The next heat pump problem on the list is the heat pump defrost board. The defrost board controls the defrost in the colder months. The heat pump condenser operates below the dew point and collecting frost and ice on the heat pump condenser coils. The ice and frost on the heat pump condenser coils need to be removed. Therefore, the heat pump is equipped with a defrost cycle that will change the unit over to the cooling cycle. This causes the condenser coils to heat up and melt the ice.
At the same time, the defrost control board activates the heat strips or backup heat inside the air handler. This is done so the occupants do not know the heat pump is on in the cooling mode. For whatever reason, perhaps they get wet or some electronic component on the board goes bad. However, the defrost control boards will go bad from time to time and need to be replaced to eliminate the heat pump problem.
Of course, the best replacement in many cases for a bad part is a direct replacement. So for the heat problem to be fixed you need to get a new defrost control board from the manufacturer. It is best to get an HVAC tech to take care of the problem. The defrost control boards are usually located inside the condenser cabinet with high voltage. There is a danger involved in changing a defrost control board.
The Reversing Valve
Specific to heat pumps the next problem one can encounter is the reversing valve. The reversing valve will shift from cooling to heating mode. Then back again depending on the setting on the heat pump thermostat and defrost control. Sometimes the reversing valve can get stuck and require a slight tap with a wrench.
If the wrench does not do the trick then other measures must be taken including possibly changing the reversing valve. Other problems that can develop with reversing valves is the solenoid can go bad and need to be replaced. Changing the reversing valve solenoid is an easy task compared to changing the reversing valve.
There are those reversing valves that leak refrigerant from the high side to the low side. Some refuse to shift and need to be replaced. To resolve this heat pump problem an HVAC technician with good brazing skills needs to replace the reversing valve. It will require all the refrigerant be evacuated. After the reversing valve is replaced the system will need to be recharged properly.
Back Up Heating
The next item specific to heat pumps that have had problems historically is with electric backup heat and systems that only have sequencers. A sequencer is an electric relay that will stage the heat strips for multistage heat strips. This is generally the case with larger systems and the engineer does not want the whole system to energize at once but instead stage the electric strips to come on slowly in a sequence.
There are specific reasons for this sequence. However, the problem with some sequencers is the contacts inside the sequencer will not work properly. In this case, the sequencer needs to be replaced. Again, this is high voltage and needs the attention of a professional familiar with the unit. There is a shock hazard involved and can be very dangerous.
Heat Pump Problems - Conclusion
These are items specific to a heat pump that can give you problems. Problems that can occur with your heat pump system. Some of these things require specific training in the proper safety procedures and for and handling of refrigerant. Sometimes it is best to call and HVAC technician to repair your system. We hope this helps you fix the heat pump problems.
For an additional resource regarding heat pumps click here.
Heat Pump Problems