There are several factors that can lead to your heat pump freezing up during the summer cooling season or winter heating season in Northwest Indiana. You can fix some of the simple problems that lead to freezing yourself, but it may be necessary to call an HVAC expert for more technical repairs.
In a nutshell, heat pumps most commonly freeze up due to any the following:
- Insufficient airflow
- Freezing rain leading to ice buildup
- Drain blockages
- Lack of maintenance
Let's look at these in greater detail.
What Causes A Heat Pump To Freeze Up?
It’s normal for heat pump coils to have a light coating of frost on them, but a thick ice buildup is a sign of operating problems that will prevent your system from heating and cooling properly and can lead to your heat pump freezing up. A heat pump has automatic controls that should send the unit into defrost mode to prevent ice buildup during normal operation. An HVAC technician can check to be sure those controls are operating correctly.
One of the main reasons why a heat pump freezes up is because of a lack of airflow. If there isn’t adequate airflow, ice can build up on the coils resulting in the heat pump freezing up.
The airflow restriction can be caused by:
- Clogged filter
- Blocked ducts
- Blockage of the outdoor unit by leaves, grass, or snow.
- Supply and return ducts are unobstructed by furniture, carpeting, or closed doors.
Conditions unrelated to the mechanical integrity of your system can also cause the heat pump to freeze up. Freezing rain or leaking gutters can let ice accumulate on your outdoor unit and block airflow.
Other Possible Reasons Why Your Heat Pump Is Freezing Up
There are a couple of other factors that could impede your heat pump’s proper operation. These include:
- Insufficient refrigerant charge
- Faulty valve operation
- A worn-out motor or fan
- Other electronic or mechanical problems that your technician should be able to identify and repair
How To Stop Heat Pump From Freezing Up
In order to keep your heat pump from freezing up, you will need to make sure airflow is unrestricted and the unit is not blocked. Some tips to prevent this problem, include:
- Cleaning or replacing the air filter regularly
- Keeping your outdoor unit free of debris
- Checking that any water that condenses in your outdoor unit is free to drain away from the equipment
- Ensuring that the concrete slab under the unit hasn’t settled or shifted to cause water to accumulate inside the condensing unit