If you’re experiencing unusual freezing up in your geothermal unit, it’s important to take it seriously because it could be a sign of a serious issue. The geothermal unit works efficiently by transferring and absorbing heat from the ground and distributing it to your home. However, when it gets too cold or freezes up, it could cause damage to the unit and hike up energy bills. In this article, we’ll delve into some of the possible causes of the freezing up of geothermal units and how to fix them.

1. Introduction: Understanding Geothermal Units and the Problem of Freezing

If you are experiencing freezing issues with your geothermal unit, you are not alone. This problem is common among geothermal unit owners and can be caused by a variety of factors. In this article, we will explore the main reasons behind geothermal unit freezing and the steps you can take to prevent and troubleshoot the issue.

First, let’s understand what a geothermal unit is. A geothermal unit is a type of heating and cooling system that uses the earth’s natural heat to regulate temperature. It works by transferring heat from the ground into the home during the winter, and transferring heat from the home back into the ground during the summer months. This process is achieved through a loop of pipes buried in the ground, which circulate water or refrigerant to distribute heat.

One of the most common issues with geothermal units is freezing. Freezing can occur when the refrigerant level is too low, airflow is restricted, or maintenance issues are neglected. Proper sizing and installation also play a role in preventing freezing. Understanding these factors and taking preventative measures can help you avoid costly repairs and ensure the long-term efficiency of your geothermal unit. Let’s dive into each of these factors in more detail.

2. The Role of Refrigerant Levels in the Freezing of Geothermal Units

Geothermal units rely on refrigerants to transfer heat to and from the ground to produce heating and cooling. The refrigerant levels need to be properly balanced and maintained to ensure the efficient and effective operation of the system. However, low refrigerant levels can cause serious issues, such as the freezing of the unit.

The lack of refrigerant in the system can lead to low pressure and temperature drop, causing the evaporator coil to freeze. When the coil turns icy, it blocks airflow through the ducts leading to decreased system performance and increased energy costs. Additionally, frozen indoor pipes can burst or cause other safety hazards if not handled quickly.

To avoid frozen geothermal units, it’s essential to conduct regular maintenance and ensure that the system is properly charged with refrigerant. The refrigerant lines should be inspected for leaks, and the unit should be professionally serviced by a technician experienced in geothermal systems.

If you suspect that your geothermal unit is experiencing refrigerant-related issues, it’s essential to seek professional diagnosis and repair services immediately. Don’t attempt to add refrigerant or address the issue yourself. Instead, contact your geothermal system provider or a professional HVAC technician with experience in geothermal units.

3. Addressing Airflow Problems and Maintenance Issues to Prevent Freezing

One of the common causes of a geothermal unit freezing up is inadequate airflow. This can be due to a dirty filter, blocked ductwork or registers, or a malfunctioning blower fan. When there is a restricted airflow over the evaporator coil, the refrigerant temperature drops to below freezing, and moisture in the air freezes on the coil.

To prevent airflow problems, it’s important to check and change the air filters regularly, at least once every three months. A dirty filter not only restricts airflow but also allows dust, dirt, and other debris to accumulate on the coil, reducing its efficiency and lifespan. In addition, make sure that the supply and return air vents are open, unobstructed, and properly sized for your geothermal unit.

Another crucial factor in preventing freezing of geothermal units is proper maintenance. Regular maintenance by a licensed HVAC professional can detect and resolve any impending issues before they cause major problems. Some of the maintenance tasks that can prevent freezing include checking the refrigerant charge and its pressure, inspecting the evaporator coil for cleanliness and condition, and testing the thermostat and controls for accuracy and proper functioning.

In addition to addressing airflow problems and maintenance issues, it’s important to ensure that your geothermal unit is properly sized and installed to prevent freezing. If a unit is undersized for your home’s needs, it may cycle on and off frequently, causing the coil to freeze. On the other hand, an oversized unit may overcool the air, leading to excessive moisture buildup and freezing on the coil. By following these preventive measures, you can avoid the hassle and expenses of a frozen geothermal unit.

4. The Importance of Proper Sizing and Installation to Avoid Freezing

Geothermal heating and cooling systems are a popular, energy-efficient alternative to traditional heating and cooling systems. However, if the system is not installed or sized correctly, it can cause freezing issues. A proper sizing and installation are critical, as it ensures that the system operates at an optimal level and prevents any freezing problems.

One of the common causes of freezing in a geothermal unit is an improper sizing of the system. If the system is oversized, it will cycle on and off too frequently, causing the evaporator coil to freeze. On the other hand, if it is undersized, it will work extra hard to meet the demand, causing the refrigerant to drop to an unusually low temperature, resulting in freezing. It’s crucial to get the unit sized properly based on the size of the home or building it is serving to avoid any freezing issues.

Apart from proper sizing, the installation of the geothermal system is critical to avoid any freezing trouble. The installation of the unit involves the correct placement of the pipes, coils, and heat exchangers. If there are any malfunctions in any of these components, the unit will stop functioning correctly. A professional contractor should carry out the installation, and it should be done according to the manufacturer’s guidelines to avoid any potential issues.

Proper sizing and installation of a geothermal system are integral to prevent any freezing issue that may arise. To ensure proper installation and sizing, it’s best to turn to a professional contractor with experience in geothermal installations. With a well-designed and installed geothermal system, homeowners can enjoy a highly efficient and trouble-free system for years to come.

5. Troubleshooting and Fixing a Frozen Geothermal Unit

If you notice that your geothermal unit has frozen up, it is important to troubleshoot the issue as soon as possible. Ignoring a frozen geothermal unit can lead to more significant problems and costly repairs down the line. Here are some steps you can take to troubleshoot and fix a frozen geothermal unit.

Step 1: Turn off the Heat Pump

If you notice that your geothermal unit has frozen up, the first step is to turn off the heat pump. Leave it off and allow the unit to thaw out completely. Running the pump while it is frozen can cause even more damage to the system.

Step 2: Check the Air Filters

Dirty or clogged air filters can cause restricted airflow, which can lead to freezing. Check your air filters and replace them if necessary.

Step 3: Inspect the Blower Motor

A faulty blower motor can also cause airflow problems, which can lead to freezing. Inspect the blower motor to ensure that it is working correctly. If it’s not, you may need to replace it.

Step 4: Check Refrigerant Levels

Low refrigerant levels can cause freezing in the heat pump. Check the refrigerant levels in your geothermal unit and add more if needed. It is best to have a professional perform this task, as handling refrigerant can be dangerous.

Step 5: Consult a Professional

If you have completed all of the above steps and your geothermal unit is still freezing up, it may be time to consult a professional. A trained and experienced technician can diagnose the problem and provide the proper repairs necessary to get your unit up and running again.

Don’t leave a frozen geothermal unit unaddressed. By following these steps, you can troubleshoot and fix the issue before it turns into a bigger problem. Remember, regular maintenance and professional service can go a long way in preventing any future freezing issues.

6. Preventing Future Freezing Issues with Regular Maintenance and Professional Service

Taking proper care of your geothermal unit is crucial to avoid future issues, including freezing. Regular maintenance and professional service play an important role in preventing such problems and ensuring that your unit runs smoothly all year round. Here are some tips to help you prevent future freezing issues with your geothermal unit:

Schedule Regular Maintenance:

Regular maintenance is one of the most important steps to prevent freezing issues in your geothermal unit. A professional technician can perform a thorough inspection of your unit to identify any issues that might cause freezing, such as dirty filters and coils, low refrigerant levels, and faulty components. Regular maintenance can also extend the lifespan of your unit and improve its energy efficiency.

Replace Filters and Clean Coils:

Dirty filters and coils can restrict airflow, causing your geothermal unit to work harder than it should. This can lead to freezing and other issues. To prevent this, it’s important to change your filters regularly and clean your coils at least once a year. This will improve the airflow and prevent debris and dust from building up inside your unit.

Check Refrigerant Levels:

Low refrigerant levels can cause freezing in your geothermal unit. It’s important to have a professional technician check your refrigerant levels regularly to ensure that they are at the right level. If your refrigerant levels are low, your technician can add more to prevent freezing and other issues.

In conclusion, preventing future freezing issues in your geothermal unit is essential to maintain its optimal performance and extend its lifespan. Regular maintenance, including filter replacement, coil cleaning, and refrigerant level checks, can help prevent freezing and other issues. Remember to schedule professional service at least once a year to keep your unit running smoothly and efficiently.

People Also Ask

Why is my geothermal unit freezing up?

There are a few reasons why your geothermal unit may be freezing up, including a dirty air filter, low refrigerant levels, restricted airflow, or a malfunctioning reversing valve.

What are the signs that my geothermal unit is freezing up?

Signs that your geothermal unit is freezing up include ice buildup on the unit, reduced airflow, decreased heating or cooling output, and strange noises coming from the system.

How can I prevent my geothermal unit from freezing up?

To prevent your geothermal unit from freezing up, it’s important to keep the air filter clean, ensure proper airflow through the vents, and have regular maintenance performed to check refrigerant levels and the reversing valve.

Can I fix my geothermal unit from freezing up on my own?

It is not recommended to attempt to fix a geothermal unit from freezing up on your own, as it can be dangerous and cause further damage to the system. It’s best to call a licensed HVAC technician to diagnose and repair the issue.

Is a frozen geothermal unit covered under warranty?

This will depend on the specific warranty for your geothermal unit. It’s important to review your warranty agreement to determine if a frozen unit is covered and what steps you need to take to file a claim.


A frozen geothermal unit is a common problem that can be caused by a variety of issues, including a dirty air filter, low refrigerant levels, restricted airflow, or a malfunctioning reversing valve. It’s important to have regular maintenance performed on your system to prevent freezing and address any issues promptly. If you suspect your geothermal unit is frozen, it’s best to call a licensed HVAC technician to diagnose and repair the problem.