When A Heat Pump Freezes, Here’s What To Do

During normal heat pump operation in the winter, you may notice that the unit’s outdoor coils accumulate some frost or even small amounts of ice. This is normal and is usually resolved when the heat pump shifts into defrost mode. If your heat pump freezes over completely, however, then it’s time to call for the assistance of an HVAC professional.

A heat pump will run an occasional defrost cycle to remove ice and frost that have built up on the coils of the outdoor unit. When the system detects ice on the coils, it briefly switches into cooling mode. This reverses the flow of refrigerant in the system and sends hot refrigerant through the outdoor coils, melting the ice and frost. During the defrost cycle, a set of supplemental heating units keeps indoor air warm.

You may be able to take some steps on your own that can help:

• Remove leaves, snow, dirt, sticks and other material that could be blocking the outdoor coil and interfering with airflow and operation.
• Make sure the gutters on your home aren’t leaking or overflowing and causing water to drip onto the heat pump.
• Take care of the unit after a winter storm that produces snow, freezing rain or ice. Water from a garden hose should be warm enough to remove accumulations of ice after a storm.

If your heat pump freezes frequently, it means there is a serious problem with the unit that needs to be fixed before it is severely damaged.

These issues will require the services of an HVAC professional:

• Refrigerant level is low and needs to be recharged.
• Defrost control or timer is not working.
• Defrost thermostat or sensor is not working.
• Defrost relay is not working.
• Reversing valve is sticking.
• The outdoor fan motor has stopped working.
• Reversing valve solenoid coil is malfunctioning.
• Unit has experienced some settling into the ground and needs to be elevated.

Customers in the Greater Cleveland and northern Ohio areas know they can rely on P. K. Wadsworth Heating & Cooling Inc. for expert HVAC service, maintenance and repair. Contact us today for more information on maintaining your heat pump and what to do if the unit freezes over.