Heat Pumps and Programmable Thermostats: Learn How They Work Together

If you’ve invested in a heat pump, you’ve chosen an economical way to heat and cool your home in our moderate San Antonio climate. Perhaps you’re thinking about adding a programmable thermostat to lower the temperature at night so you’ll save on energy consumption over the winter. Before you do, it’s important to understand how programmable thermostats work with heat pumps, so you can make an informed purchase.

How heat pumps work:

Your heat pump system draws warmth from the outside air to heat your home slowly and efficiently, and it raises the temperature by one-degree increments. For those times when outdoor temperatures dip below the point where there’s enough warmth available, heat pumps also have an auxiliary heat source. This is either a gas furnace or an electric resistance element that’s considerably less efficient and more expensive to operate, so it’s best used strictly as an emergency backup. But, anytime your thermostat setting changes by two degrees or more, this back-up heat source automatically kicks in.

How programmable thermostats work:

  • Programmable thermostats that are used with furnaces don’t work well with heat pumps. These thermostats are essentially timers that are programmed to tell a furnace when to cycle on, and then cycle off again. If they’re used to control a heat pump, the rapid rise in temperature that occurs will cause the auxiliary heat to come on to reach the target temperature as quickly as possible. This uses more energy, which will increase your home heating bills.
  • The programmable thermostats that are designed especially for heat pump technology operate differently. They employ an “intelligent” algorithm that actually calculates the length of time necessary to raise the temperature in a home slowly, one degree at a time. By doing so, the need for inefficient auxiliary heat is avoided. When choosing one of these programmable thermostats, you need to make sure it’s compatible with your specific heat pump model.

For advice about the right programmable thermostat for your heat pump, contact us at Beyer Boys. We’ve been helping San Antonio area residents with their home comfort needs since 1990.

Our goal is to help educate our customers in the greater San Antonio, Texas area about energy and home comfort issues (specific to HVAC systems).