Tuckers Air Conditioning, Heating & Plumbing Blog

Why Your Heat Pump Won’t Switch Modes

One of the biggest advantages that heat pumps offer is the ability to act as either heating or cooling systems depending on demand. This is certainly one of the biggest reasons that homeowners install heat pumps in the first place. This ability also opens up a couple of unique problems, though, including the system becoming stuck in one mode. Let’s take a look at how the heat pump actually switches between modes, and what’s happening when it becomes stuck in one mode.

The Reversing Valve

The heat pump is able to switch between heating and cooling modes thanks to a part called the “reversing valve.” This valve sits in the refrigerant line, and contains a slide that moves between two positions. The slide is controlled by an electromagnet called the “solenoid.” When the heat pump is in heating mode, the solenoid moves the slide to one side of the valve and the direction of the refrigerant is changed. The outside unit of the heat pump absorbs heat and the inside unit vents it into the home. In cooling mode, the slide is moved to the other side of the valve and the refrigerant flow is reversed. This causes the heat pump to siphon heat from inside the home and vent it outside.

Possible Problems

If your heat pump won’t switch between modes, it means that one of two things has happened. Either the slide is stuck in the valve, or the solenoid has lost its charge. If the slide has become stuck, the valve can often be disassembled to free the slide and then reassembled to resume operations. If the solenoid is dead, though, it will have to be replaced.

If your heat pump is stuck in one mode, call Tuckers Air Conditioning, Heating & Plumbing. We offer a full range of heat pump services throughout Potomac, MD.