How to deal with frozen heat pump during winter

Though a heat pump can freeze during summer, you are more likely to experience a frozen heat pump during winter frequently. This kind of problem often happens with HVAC units. This can be very frustrating to deal with because you need your heating system more during winter. In this article, you’ll learn how to deal with frozen heat pumps during winter.

First, let’s understand what can cause your heat pump to freeze.

Snow or frost build-up on the unit

The primary cause of a frozen heat pump in the winter is snow or frost. During this weather, it is natural for snow and frost to gather everywhere. Similarly, they can accumulate on the unit and cause it to freeze. You need to be careful when you attempt to remove the snow. You cannot do that with a sharp object unless you are ready to risk damaging some part of the heat pump. You can melt the snow or frost with water.

Dirty or clogged coils

Another major cause of a frozen heat pump is a clogged coil. Heat pumps come with two coils. During winter, things like snow, debris, and dirt can easily accumulate and choke the coils. This will subsequently prevent air from flowing adequately through the system. The effect of this is that the defrost cycle may not impact the frozen heat pump in any way.

To fix this, you will need to unclog the coil by cleaning it. Clear out any dirt in the environment that can likely tamper with the efficiency of this system.

Water dripping on the unit

Whenever water drips on the unit during winter, it is usually in the form of freezing rain. Once the dripping water gathers on the unit and it’s not cleaned off, it will eventually freeze up and result in a frozen heat pump.

Placing your heat pump unit where the rain cannot touch it will prevent this problem. However, suppose you have already installed the unit, ensure that you clean the dripping water before it gathers on the unit.

Water from the ground

It is possible that you have a frozen heat pump because the unit sank into the ground. This means that freezing rain is not the only cause of frozen heat pumps, water from the ground is also enough to cause this problem. You will need to increase the distance between the ground and your unit using a concrete slab. This will ensure that the unit does not get sunk into the ground again.

How to deal with a frozen heat pump during winter

Exploit the defrost cycle

Let the heat pump enter the defrost cycle. This will be more effective if the unit is covered with a thin layer of snow. However, if there is a lot of snow, the unit’s defrosting cycle may not be helpful.

What is a defrost cycle?

A heat pump has three cycles: the heating cycle, the cooling cycle, and the defrost cycle. The first two are responsible for keeping the temperature high when needed and cooling the system when required. However, our focus here is the defrost cycle.

The defrost cycle is responsible for keeping the heat pump from freezing up. Here is how it works.

Your heat pump is designed with a sensor that passes across to the system that the outside temperature is lower than 30 degrees Fahrenheit. Once the system detects this development, it automatically goes into defrost cycle.

This is affected by the reversal of the valve, which then allows the refrigerant to run backwards. This immediately extracts heat released to the inside and delivers the heat to the outdoor coil, which melts the ice and defrosts the system. This is put in place to ensure that you do not have to worry about defrosting your heat pump. But, it is not always enough.

It’s easy to know when your heat pump automatically goes into defrost cycle because the indoor heat is stopped temporarily. However, this does not mean the inside becomes cold immediately. Your heat pump also comes with a supplement system that keeps the indoor temperature stable for the time being. Another way to know that your heat pump is on defrost cycle is that the indoor and outdoor fans also stop working, leaving only the compressor operating. Defrosting can last for up to 10 minutes.

The fact that the built-in defrost cycle is not always enough to deal with a frozen heat pump during winter is why you need this article. Not solving the problem of a frozen heat pump can cause it to keep jumping into the defrost cycle, and this can cause damage to the system.

Call a technician

After trying the defrost cycle, and you’ve also tried removing the debris and dirt, but you’re unable to find the cause of the frozen heat pump, it is advisable to enlist the services of a technician from a trusted company like the ones from this site to help you look into it and get it fixed. You shouldn’t keep checking the unit yourself as this can cause you to tamper with some parts of the heat pump, which could lead to even bigger problems.


While fixing your frozen heat pump yourself is possible, periodic maintenance is still advised. This is to save you the unpleasantness of having to endure a cold day while waiting for the technician to fix your heat pump if it develops a major problem. Also, maintenance is cheaper and more efficient than waiting for a problem to develop before calling a technician.