The Problem with Heat Pump Ice

If you notice ice forming on your heat pump this summer, you shouldn’t ignore it. Heat pump ice is not an indication that the system is cooling properly, though many homeowners seem to think that. Rather, it means that your heat pump is experiencing a problem which could cause the entire system to break down. Let’s take a look at why this happens, and what it can lead to.



In order to understand why ice forms on your heat pump, you must first understand how the system cools your home. Heat pumps produce cool air by evaporating refrigerant in a coil inside the indoor unit. This siphons heat out of the air around the coil, and the now-cooled air is blown into the ducts. Condensation forms on the coil, and siphons out of the system afterwards. The constant flow of warm air from the ducts maintains a temperature balance around the coil, so that it never drops below freezing. If the flow of warm air is interrupted, as happens with a clogged air filter or a broken air handler, the temperature of the air around the coil will drop low enough that the condensate freezes. This will cause the evaporator coil to ice over.


While the coil is frozen over, the heat pump will not be able to siphon heat from the air in your home as effectively. This will cause your system’s output to drop. The ice can also build up enough that the weight of it will permanently warp the coil, requiring that it be replaced. If the ice still isn’t cleaned off, it will spread down the refrigerant line to other parts of the system. This will cause them to malfunction, and eventually the system will breakdown.

Magnolia Plumbing, Heating & Cooling offers comprehensive heat pump repair services throughout Fairfax, VA.