Schmitt -- Commercial Heat Pump -- 02-23-16

Commercial Heat Pump Troubleshooting

Like any commercial appliance, heat pumps sometimes have mechanical issues. Below are troubleshooting ideas for some of the more common problems.

  1. Heat Pump Icing Up

If the top of your unit has a lot of ice, if ice is incasing the coils, or if the whole unit has a thick sheet of ice and snow covering it, you’ll want to take action. That much ice can prevent heat from transferring between the refrigerant and the air outside, and it will impede the heat pump’s operation. Any heat pump covered in ice should be attended to quickly, or the unit could become severely damaged.

Troubleshooting for Iced Heat Pumps

What you’ll need to do to fix your unit is dependent upon the type of problem it’s experiencing.

  • The unit isn’t defrosting—If the unit doesn’t defrost periodically like it should, ice will build up quickly. Faulty relays, sensors and controls can all cause defrost issues. The reverse valve, which makes the unit switch from heating to air conditioning, may also have a problem.
  • There is a problem with the outdoor fan—The motor of the fan might be failing or dead. Alternatively, the fan itself may be damaged, which makes it difficult for the heat to release from the unit and causes an accumulation of ice.
  • The refrigerant level is low—Slow leaks of refrigerant can keep the system from producing enough heat, which is needed to melt the frost.
  • The outdoor unit is blocked—Piles of snow can accumulate around the outdoor unit, which impedes the airflow and causes more icing.
  • There is water leaking onto the unit—If water is constantly dripping onto the unit from leaking gutters, it can cause a layer of ice to gradually form on top.

In order to troubleshoot the issue, melt the ice with water from a hose (never use a pointy object). Remove any debris or snow that is blocking the unit. See if any leaking gutters are causing water to drip onto the unit. Repair any you find. Call your HVAC company to troubleshoot further.

  1. Troubleshooting for a Heat Pump that Runs Constantly


A heat pump can run constantly in the summer if it is set to a low temperature in very hot weather. If this isn’t the case, your system might be too small and thus be unable to adequately heat the space, or the space may not be insulated well enough to retain the heat. Another culprit is a system that hasn’t had yearly maintenance, as it may have a buildup of debris.

Heat pumps run longer and heat less than furnaces. However, if in the winter the temperature is warmer than the mid-30s and you still find that it’s running all the time, you might have leaking refrigerant, a compressor problem or a frozen outdoor unit. A service technician can help you determine the problem.

Your HVAC company can help you with ice problems and systems that run too frequently. The company can also help with heat pumps that blow cold air instead of warm. Whatever type of issue your heat pump is experiencing, a qualified technician can help determine and fix the problem.


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