Why Is My Ductless Heat Pump Not Heating My House?
There’s nothing more frustrating than a heat pump not heating, especially as temperatures begin to drop. There are many reasons why a mini-split may malfunction. Exploring the potential causes can help you decide whether it’s necessary to call a heat pump repair technician.
Blocked or Dirty Exterior
For a heat pump to operate properly, it needs to absorb heat from the outside air. Through a refrigerant, the heat pump then transfers the accumulated heat inside to warm the air inside your home. If your exterior unit is dirty or covered in debris (like leaves, grass, snow, or ice), it is unable to capture the warmth from outside. Without this necessary step, the air inside your home will not heat up.
Clogged Air Filter
Ductless heat pumps work by warming air via an evaporator coil. However, if the air filter leading to this coil is clogged or dirty, your heat pump may lack the necessary airflow to blow warm air into your home. To determine if this is the potential reason your heat pump isn’t working, you should open the indoor unit’s front panel to inspect the filters. If you see that there is any buildup on the filters, you can simply remove the filters and vacuum them.
Insufficient Refrigerant Charge
If you find the heat pump is not dirty or blocked by debris, the issue may be your heat pump lacks the necessary refrigerant charge to heat the air. A low refrigerant charge could be caused by a leak, causing the refrigerant liquid to escape the unit. Without enough refrigerant, your exterior unit will be unable to capture and transfer the outdoor heat inside.
Reversing Valve Malfunction
Your home’s heating, ventilation, and air conditioning system (or HVAC) contains a valve that determines in what mode your heat pump operates. During warm months, it should be switched to its cooling function, and it should be set to warm during the colder months. If the reversing valve is damaged, your home’s HVAC system will be unable to switch from cooling to heating.
Depending on where your indoor unit is installed, you may not feeling the warm air. The temperature of the room is taken at the indoor unit. If you are feeling that the temperature is not warm enough where you are, turn the heat up by a few degrees on your remote. Think of the number on the remote as a setting, not a temperature and don’t be afraid to turn it up! In some cases, this still is not sufficient and we suggest installing an accessory thermostat like the Honeywell D6.