If you’re using a heat pump to keep warm this winter, you may notice ice starting to form on the outside coil. If you do see this happening, don’t panic. Heat pump ice is to be expected if certain conditions are met, and the system is designed to deal with it. However, the ice can definitely become a problem if the system’s countermeasures fail. Let’s take a look at why it happens, and when you should call for professional help.
Why Ice Forms
A heat pump warms the home by evaporating refrigerant in the outer coil to siphon thermal energy from the surrounding air. As the heat is leeched from the air, the temperature around the coil drops. Condensation forms on the coil as the air cools past the dew point. If the air temperature drops low enough, the condensate will freeze and form ice.
When to Call for Repairs
If heat pump ice is allowed to build up unhindered, it will cut off the coil from accessing the surrounding air. Without that access, the heat pump won’t be able to adequately heat the home. The weight of the ice can also eventually warp the coil, necessitating its replacement. Finally, unfettered ice buildup can move down the coil to other parts of the system and cause further problems, up to and including a full breakdown.
Heat pumps are designed to combat ice by using defrost cycles, in which they vent heat through the outside coil to melt the ice. If this cycle malfunctions, however, your system could be in trouble. If you notice that your heat pump coil is more than half-covered in ice, you should call a professional just to make sure that everything is operating properly.