Tuckers Air Conditioning, Heating & Plumbing Blog

The Reason Your Heat Pump is Stuck in AC Mode

If you’re using a heat pump this winter, you probably expect it to actually, you know, warm your home. If the heat pump is blowing cold air instead of warm, it means that the system has likely become stuck in air conditioning mode. There is only one likely explanation for that kind of problem, though the specifics may vary slightly. If your heat pump is stuck in AC mode, read on to find out the reason why.

The Reversing Valve

The reversing valve is the part of the system responsible for switching the heat pump back and forth between heating and cooling modes. It is a four-way valve that sits in the refrigerant line. Inside the valve is a slide, which is moved back and forth between two positions. Depending on the position the slide is in, the refrigerant in the system will flow one way or the other to determine whether the heat pump heats or cools the home. The slide is controlled by an electromagnet called the solenoid. An issue with the reversing valve definitely has the potential to “freeze” your heat pump into heating or air conditioning mode.


There are two ways that a reversing valve can malfunction in such a way that the heat pump becomes stuck in one mode. The first is that the slide is simply stuck in the valve. Having a professional open the valve and reset the slide is the ideal way to deal with this. The other way is that the solenoid has lost its charge, and can no longer move the slide. If this has happened, the only thing to do is to have the solenoid replaced. Either way, repairing the valve should take care of the problem.

Tuckers Air Conditioning, Heating & Plumbing provides heat pump repair services throughout Rockville, MD.