Traditionally heat pumps are used in moderate climates such as the southern states but with a supplemental heating source they can be used in the midwest.

How Heat Pumps Work.

frozenheatpumpsA heat pump works similar to a refrigeration system but it can be reversed to either provide heat or cooling. During the winter a heat pump performs the function of a furnace, extracting heat from the outdoors and moving it to inside your home or commercial building. During the summer the system serves the same purpose as an air conditioner, cooling the air by moving heat from the inside to the outdoors.

An advantage of heat pumps is that they moves heat instead of generating heat, giving you more energy efficiency. According to, “heat pumps can provide equivalent space conditioning at as little as one quarter of the cost of operating conventional heating or cooling appliances”.

So to recap. The benefits are:

  • Savings of up to 40% on operational cost
  • Eceptionally Quite Operation
  • Less emmisions into the enviroment
  • Efficiency (Superior SEER rating)

While this kind of savings may spark your intrest in heat pumps, there is a catch.

When Your Heat Pump Freezes.

Heat pumps dont like the sub zero weather like we’ve had in St. Louis this past winter. There is a point when the heat pump can no longer pull cold air out of the indoors, especially on these winter nights, and therefore your furnace will have to pick up the slack. With heating mode, refrigerant inside the indoor coil becomes very hot and transfers the heat energy to indoor air. The coil outside, in heating mode, becomes artic cold in order to absorb heat energy from the very cold winter air. Its possible that the heat pump will freeze up if the defrost mode is unable to keep up with the ice forming on the unit.

These are some common causes and troubleshooting tips for a frozen heat pump:

  • Airflow – To instigate heat exchange by the refrigerant the coils must receive airflow. Ensure that the outside unit doesn’t become covered with ice or snow. Ice accumulation is a possible symptom due to a lack of airflow across the coil will. You can wait for the ice to melt or use hot water. You should also check the air filter or have it replaced. Using a coil clearner and keeping the coils free of debree is part of yearly maintenance and is a service we offer at Tristate Mechanical for those who prefer hands-off service.
  • Malfunctioning equipment – When the heat pump is running the condensing fan motor should kick on and blow air out through the fins. If this is not happening then its possible the blower motor went out.
  • Refrigerant – Either too much or too little refrigerant charge can causes ice accumulation. Call Tristate Mechanical to remedy this issue.
  • Defrost mode – The demand defrost mode may not be working correctly. This is an issue for our HVAC technicians to remedy. There could be a faulty reversing or relay switch in need of replacement.

Maintaining your equipment to prevent future problems, unexpected costs, and keeping your cooling and heating system at peak performance is what we are here for. Give us a call if you would like to discuss heat pumps or if you need service.