Understanding Why the Heat Pump in Your Fairfax Area Home Is Freezing Up

Knowing what to do when you find your Fairfax area home’s heat pump freezing up can mean the difference between a momentary interruption and an expensive repair visit. Here are some quick trouble-shooting tips to help you decide if you can solve it yourself, or you need your friendly HVAC contractor on the scene.

Breathe Easy

The heat pump, not you. Make sure nothing is interfering with airflow around the heat pump’s outside condenser/compressor. No snow piled up around the outside unit, no leaves or twigs, tall grasses or plants blocking it. In built-up areas around Fairfax and Alexandria, people feel compelled to hide their heat pump condensing units behind decorative fencing, but then fail to notice snow and debris piling up inside the fenced-in area. Blocked airflow increases condensation, which reduces efficiency or, worse, can freeze on the outside unit.

Clean the evaporator coils and change the indoor filter to improve indoor airflow, too.

You’re Heat Pump is Cold as Ice

Ice buildup can interfere with the fan. If freezing rain or sleet is responsible for your heat pump’s outside unit freezing up, shut the system down to prevent fan blade damage. Soft copper lines are inside the unit – no hammers or ice picks allowed! Pour extremely hot water over the unit if you do not want to wait for natural melting.

When you are outside, look above the condensing unit to ensure no overflowing gutter is dripping icy water onto the appliance. The unit is already trying to shed humidity, so steadily adding more water impacts efficiency and may lead to your heat pump freezing up.

Sinking Foundation

When installed, your heat pump’s outside unit sat high on a concrete pad. Over time, the entire pad and unit may have settled into the ground. It may now be too low to shed water. Result? Heat pump freezing up!

None of the Above

Other issues, such as failure to defrost, could be caused by one of these:

  • a bad defrost timer
  • bad reversing valve solenoid coil
  • a bad defrost relay

To help you diagnose the reasons for the heat pump freezing up at your Northern Virginia home, please contact us at HVAC & Plumbing Unlimited Heating & Air Conditioning.