November 20, 2022
Heat Pump in Bethany, OK

Heat pumps are a great choice in Oklahoma City and surrounding areas. They will reduce your energy costs and ensure your home stays warm all winter and cool throughout the summer. A heat pump sits outside your home and is almost identical to a central air conditioner except for one major difference. Both units use refrigerant to capture latent heat from a home and transfer it outside. The difference is that a heat pump can change which direction the refrigerant flows in order to capture heat from the air outside and transfer it inside to warm up the building. Let’s take a more in-depth look at how this process works so you can better understand how heat pumps switch from cooling to heating and back again.

How the Reversing Valve in a Heat Pump Works

The reversing valve is the main thing that makes a heat pump different from a central AC unit. In any central AC system, cold refrigerant flows from the outdoor unit to the evaporator coil inside. Hot air is blown over this coil, and the heat energy in the air naturally flows into the refrigerant and almost instantly cools the air. This process quickly raises the temperature of the refrigerant and turns it from a liquid into a gas. The heated refrigerant is then pumped back to the outdoor unit so that the heat can then be released, and this process works the same with either a heat pump or a central AC unit.

When you switch your thermostat over from cooling mode to heating, the heat pump automatically activates the reversing valve so that the refrigerant then flows in the opposite direction. This means that the refrigerant now flows inside as hot gas and then turns into a cold liquid before flowing back outside to the heat pump. Changing the direction that the refrigerant flows is essential. Otherwise, it would allow liquid refrigerant to flow into the compressor if the system still ran in the same direction. If any liquid refrigerant flows into the compressor, it can seriously damage it and potentially ruin the heat pump altogether.

The process of heating starts by first compressing the hot gas refrigerant, which releases all of the heat and instantly turns the refrigerant into an extremely cold liquid. This refrigerant then moves into a series of coils inside the heat pump. The unit’s fan draws air over the coils, and any heat energy flows from the air into the refrigerant. Eventually, the refrigerant absorbs enough heat to again turn it into a hot gas. This then flows to another coil inside the building. Finally, the blower fan forces cold air from inside the building over the coil filled with hot refrigerant, and the heat then flows out to raise the temperature of the air.

What Does It Mean If a Heat Pump Won’t Switch Between Modes

One fairly common issue can occur as a heat pump ages. The problem involves the system suddenly working only in one mode. Your heat pump will automatically turn on and run as needed when set to one mode, but it won’t start when you switch your thermostat to the other mode. If you ever find that your heat pump won’t turn on, the first thing you should always do is check whether it will turn on in the opposite mode. When it runs in one mode and not the other, it means that the reversing valve has failed.

A failed reversing valve will prevent the unit from being able to change which direction the refrigerant flows. As a result, the system will get stuck in whatever mode it worked in last. If the valve fails to activate when you try to switch from cooling to heating, the unit won’t ever turn on when set to heating. While this means that you won’t have heat until you can have a technician replace the reversing valve, it is actually a good thing that the heat pump won’t run as otherwise liquid refrigerant would enter the compressor and potentially cause serious damage.

Expert Heat Pump Services in Oklahoma City

If you would like to find out more information about heat pumps and how they work, TS Heat & Air is here to help. Our technicians specialize in heat pump inspections and repairs, and we also can help with maintenance and new heat pump installation. We work on and install furnaces, central AC units and air purification systems as well. If you need any heating or cooling service in the OKC area, contact TS Heat & Air today.

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