Heat pumps usually have a bit of frost around the coils which is completely normal. However, should your heat pump become frozen, you may have a bit of a problem on your hands. If you experience a frozen heat pump, it is important that you follow the steps below.
Adjust the thermostat
Unfortunately, there are very limited solutions as to what a home owner can do once a heat pump has frozen, especially in sub-freezing temperatures. The first thing you would want to do is to set the thermostat to “Emergency Heat”. This will prevent the heat pump outside from running and possibly causing damage to the unit itself due to the buildup of ice and frost. This setting will allow the auxiliary heat in the home to maintain a comfortable temperature while waiting for diagnosis and repair of the issue that caused the freeze up in the first place.
After you’ve adjusted the thermostat, you would then need to call an HVAC professional to have a knowledgeable and helpful technician begin the process of restoring proper operation to the heat pump system. In truth, unless the air temperature is high enough to melt the ice naturally, the outdoor unit will stay frozen until it warms up. The key to that is the unit has to be shut off (turned to emergency heat at the thermostat) so that it doesn’t continue to build ice. Even then, the unit must be ice free before a technician can run it and make a proper diagnosis. Any remaining ice on the coils will skew the pressure and temperature results which the technician need to determine proper refrigerant charge.
Why it freezes
A heat pump can freeze due to several reasons. Inside blockages such as clogged filters and blocked air ducts will restrict airflow, causing the heat pump to freeze. Blockages can also occur outside directly on the unit. Freezing rain, leaves, tree branches, leaking gutters and other debris will also block air flow. Low refrigerant levels, poor insulation and a cold winter can also be the cause of a frozen heat pump.
Although you can’t control the weather, there are some things you can do to help prevent your heat pump from freezing. Make sure you change the filter once a month or as needed. Clear any obstructions in your home that could be blocking your air ducts such as furniture. An outdoor heat pump should not be directly on the ground but on a cement slab or lifted up by blocks. Adjust your gutter so water and other debris cannot drip or fall onto the heating pump.