A Few Things To Know About An Important Heat Pump Component: Reversing Valves
One of the biggest distinguishing features of a heat pump is the reversing valve. The presence of this component is the major difference between an air conditioner and a heat pump.
Although air conditioners and heat pumps work in much the same way, the reversing valve of a heat pump allows the heat pump to both heat and cool. Therefore, the reversing valve increases the importance of a heat pump in the home. While an air conditioner is only used in the summer time to cool a home, a heat pump is used year round for both heating and cooling.
Function and operation of the reversing valve
The reversing valve's function is indicated by its name. It is responsible for reversing the direction in which refrigerant flows in the system. When the reversing valve is used, the heat pump switches between heating and cooling.
A homeowner manipulates the reversing valve when he or she presses a thermostat button that will make the heat pump's solenoid - an electrical system component - slide the valve in the opposite direction. This changes the reversing valve's mode to either "relaxed" or "excited". Depending on the heat pump model, either of these modes could indicate that the heat pump is in heating mode as opposed to cooling mode.
Three possible malfunctions of the reversing valve
The valve becomes stuck in one position
If the reversing valve becomes stuck in one position, it will not be able to switch from heating to cooling or vice versa.
The valve typically works due to a pressure differential, and it will not switch over properly if the pressure in the pilot valve is lost due to an air leak or another malfunction in the system.
The valve's coil is defective
The solenoid that is responsible for directing the valve has a coil that can become defective if it loses its magnetic field. A defective solenoid coil will prevent the reversing valve from switching between modes.
The valve develops an internal leak
If the reversing valve develops a leak, the heat pump will both heat and cool the home less effectively. Unfortunately, it's not easy to troubleshoot a leak in the reversing valve.
The symptoms seen when a reversing valve has a leak are the same as those seen when a heat pump's compressor is not reaching its full capacity while pumping. However, a reversing valve leak can be identified by an excessive difference in temperature between the evaporator's suction line and the reversing valve's permanent suction line.