It’s normal to see some frost on the heat pump unit, especially during the winter. Excessive amounts of ice, however, can cause damage to your heating system and cause it to stop working completely.

Don’t be left out in the cold! Find out when you should be worried about ice freezing on the heat pump.

Heat Pumps Often Ice Up During Cold Weather

If you check on your heat pump and find that the is covered in ice, don’t panic. This is normal during periods of cold weather, like the winter months in Pennsylvania. When the heat pump is working to heat your home, it’s normal for a bit of frost to form on the coils. This happens when the pump generates heat, the refrigerant turns to gas and then condenses when it meets the outdoor coil. In winter temperatures, this condensation will freeze. That’s why the pump also has a defrosting function.

A well-running heat pump works in cycles. Periodically, the coil will collect a layer of frost or thin ice when it’s cold outside. Then, when the unit reaches a certain point, the defrost cycle should automatically switch on to keep the pump working normally. As long as the condensing fan motor can pull air into the unit, there is no need to worry.

Heat Pump Defrost Cycle

The defrost function is necessary for cold climates, like Pennsylvania, to keep the heat pump from icing over completely. In order to save energy, it doesn’t run constantly; instead, the heat pump runs defrost cycles only when it’s necessary. The unit is equipped with temperature sensors which trigger the defrost function. These cycles usually only last 10 to 15 minutes, depending on the conditions. Yet the brief defrost cycles should be enough to keep the unit functioning efficiently throughout the winter.

When Ice Buildup Is a Problem for Heat Pumps

If the heat pump is not able to defrost properly or quick enough, it could damage the unit or cause it to malfunction. Coils that are completely blocked by ice are not able to efficiently pull in cool air from the home. This will noticeably decrease the system’s heat output capacity as well.

When air cannot pass between the fins, continuing to run the heat pump may cause further damage. Severely iced up heat pumps can break the fan blades, impact the function of the outdoor coils, cause refrigerant leaks and damage other components.

Avoid serious damage to the equipment and wasted energy consumption. If you suspect that your heat pump is blocked by ice, it’s important to have it checked by a certified HVAC technician.

Signs of a Problem

Here are some signs that might signify that it’s time to call for professional help with your heat pump.

  • The entire heat pump unit is frozen over.
  • It has been frozen over for a long period of time.
  • The top of the unit and inner coil seem to be covered in ice.
  • The defrost cycle does not seem to be activating.
  • Air is not being pulled into the fins of the unit.

Why Heat Pumps Ice Up

Ice buildup which blocks the heat pump from functioning properly is usually a sign that there is a bigger problem going on with your unit. It could be a symptom that:

  • Refrigerant levels are low.
  • It’s time to replace the air filter.
  • A component inside the heat pump unit is faulty, such as the thermostat, temperature sensor or refrigerant metering device.
  • The blower’s fan blades or coils are blocked by buildup.
  • The outdoor blower motor is malfunctioning.
  • The reversing valve is stuck.

What to Do If the Heat Pump Isn’t Defrosting

If your heat pump is blocked by ice or doesn’t seem to be defrosting enough to allow it to run normally, there are a few things you can check. Make sure that the air filter is in good condition. Replace the filter if it seems to be full of buildup. Next, inspect the fins of the condensing fan. Be sure to clear away any leaves or debris that may be blocking regular function. Then, set turn on the fan manually at the thermostat. If no air output comes through the vents, it could indicate a problem with the blower motor. Finally, call your trusted heating repair company to report your findings and request assistance.

Find more information in our related posts about How Snow Can Impact Your Furnace and HVAC and 10 Ways to Winterize Your Home.

Schedule an Inspection Today

AQM provides inspections, repairs and maintenance services for heat pumps, generators, and furnaces throughout Chester, Delaware and Montgomery County. We also carry a wide selection of gas log fireplaces and whole-house humidifiers.

For help keeping your home warm all winter long, consider our convenient maintenance plans to keep your system running well all year long. You can also request an estimate online or call AQM at (610) 363-3940.

AQM, Inc.