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How To Use The Defrost Mode On Heat Pumps

By All-Temp Heating & Cooling

Date Published: November 11, 2022

Whether you dread the chilly months or welcome their return, it is important to understand proper maintenance of your heat pump. As most residents know, snow and frost is nothing new to Staunton. Frost can harm the efficiency of your heat pump and result in an uncomfortable situation. However, heat pumps have a cycle called defrost mode to help keep the system running properly. In this blog, we will discuss the ins and outs of your heat pump’s defrost mode.

Heat Pumps 101

Contrary to its name, heat pumps provide heating and cooling to your home or space. Rather than creating heat, heat pumps simply transfer heat depending on the setting. In cooling mode, the device absorbs warm air inside your home and transfers it outside. In heating mode, the device does the opposite and absorbs heat from the air or ground and releases it inside.

Heat pumps are best for climates such as Staunton, because temperatures never get low enough in the winter for the device to not pull heat from the air. The heating and cooling device is extremely energy efficient due to it transferring heat rather than creating it.

What Is Defrost Mode?

When snow or frost hits Staunton, it is important to take care of your outdoor heating and cooling units. Frost can accumulate on the outdoor coils and other parts of your heat pump and harm efficiency. Ignoring frost can lead to a variety of consequences, such as:

  • Overworked Unit
  • High Utility Bills
  • Costly Repairs
  • Uncomfortable Home Temperatures
  • Unit Breakdown

However, your heat pump can be prepared when frost hits with defrost mode. Defrost mode on heat pumps works to eliminate frost from the outdoor coil and keep your system working effectively.

How Does Defrost Mode Operate?

Defrost mode is typically activated when temperatures drop below 32 degrees, but methods can vary depending on the heat pump manufacturer. When defrost mode activates, your system switches from heating to cooling mode, and hot refrigerant is sent from the indoor air handler to the outdoor coil. A simple way to tell if defrost mode is working is if you hear the reversing valve switch from heating to cooling mode. A defrost cycle can run up to 10 minutes and repeat the process until the coil temperature has reached 57 degrees and frost has completely melted.

Types Of Defrost Methods

Your heat pump either operates on time-temperature or demand defrost mode. An All-Temp technician can help identify which defrost method your system operates on. Below we will discuss the difference between time-temperature and demand defrost modes on heat pumps.


The time-temperature defrost method occurs on a set schedule, which shuts on and off at constituent times. This method will activate regardless of if your heat pump coils are frosted or not. The time intervals can be selected by an All-Temp technician and are determined based upon the climate where the heat pump is installed. Time-temperature defrost mode typically ranges every 30, 60, or 90 minutes of actual running time.

Demand Defrost

Heat pumps with demand defrost have a sensor that can tell when frost is forming on the coil. The device can sense the coil and outdoor temperature and activate in the presence of ice. This mode can save energy by only defrosting when necessary.

Why Defrost Mode Isn’t Working

It is important to pay attention if your heat pump’s defrost mode is effectively removing frost. If defrost mode is not eliminating frost from the coil, there is likely a malfunction. Below are possible causes to why defrost mode on your heat pump is not working.

  • Refrigerant Leak
  • Faulty sensor
  • Dirty or damaged coil
  • Thermostat issues
  • Clogged unit

One of our expert technicians can help repair your heat pump’s defrost mode and quickly restore your home’s comfort. However, we recommend ensuring the problem is not a minor issue, such as clogged leaves or snow build up.

Our main goal is to keep your home comfortable and energy bills low this winter. Before the first frost in Staunton hits, it is important to understand the process of defrost mode on your heat pump. Understanding the process can help catch issues early before they result in a costly repair! For heat pump maintenance, repair, or installation, give one of our expert technicians a call!