Why does my heat pump use auxiliary heat?

A heat pump’s auxiliary heat mode flips on automatically when it needs to heat your home fast. If this backup heat source switches on, it may mean the temperature outside is very cold, your thermostat is set higher than normal, or your heat pump may be malfunctioning.

What is auxiliary heat?

Auxiliary heat is a feature that works in conjunction with heat pumps. Unlike a furnace, a heat pump does not create its own heat but takes it from the outside air, so they use less energy to run. This means lower electricity bills for a comfortable home. However, heat pumps take a while to reach the desired temperature. This is where the auxiliary heat feature comes in. When your heat pump cannot heat your home quickly, it will switch to auxiliary mode as a backup. Auxiliary heat and your heat pump were designed to work together to keep your home comfortable.

When your auxiliary heat switches on, there is usually no reason to be concerned. Here are a few reasons why the auxiliary heat mode will turn on:

the outside temperature

If the temperature is below 35˚ F, there is not enough heat in the air and your heat pump will switch over to auxiliary mode to quickly heat your home.

your thermostat setting

The auxiliary heat will turn on if your indoor thermostat is set more than 2˚ F higher than the outside temperature. For example, if you wake up in the morning and your thermostat says 62˚ F and you raise it to 65˚ F, the system will automatically turn on the auxiliary heat mode to help heat your home to the desired temperature.

The heat pump is defrosting

When it is unusually cold out for an extended period, ice builds up around the coils on the unit causing it to go into defrost mode. During this cycle, the heat pump uses the hot air from your home to melt the ice on the coil while the auxiliary mode switches on temporarily to heat your home.

Emergency heat setting is turned on

The emergency heat setting on your thermostat is set to on. This setting turns off the heat pump completely and should only be used during an emergency.

Signs that your auxiliary heat is not operating correctly:

  • The auxiliary heat does not turn off when you lower your thermostat.
  • The defrost mode stays on. It should only stay on a few minutes.
  • Your electricity bill is higher than normal.
  • Your heat pump runs in auxiliary mode for an extended amount of time.

Call Burkholder’s for heat pump repair

If you are concerned about your heat pump, consider contacting a professional. Burkholder’s is your best home comfort pro that specializes in air conditioning, heating, and air quality services. We offer services in Allentown, Bethlehem, Emmaus, and surrounding areas. Our technicians will diagnose the problem with your heat pump and repair it. If you need emergency heat pump repair we have you covered. We also provide maintenance services even if we didn’t install your heat pump. Contact us today!