How Concerned Should You Be If Your Home’s Heat Pump Freezes Over?
How concerned should you be if your heat pump freezes over? Maybe not very—at least, not just yet. If a light coating of frost appears on the heat pump’s external coils, as well as the refrigerant lines that run into the house, it probably just means the outdoor temperature’s dropped to 40 degrees or below and the amount of water vapor in the air is above 70 percent. Since the heat pump coil typically runs about 20 degrees lower than the outdoor temperature, dew forming on the cold coil and refrigerant conduit freezes into a dusty layer of frost.