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Your Indianapolis Licensed HVAC Contractor


Your Indianapolis Licensed HVAC Contractor


Vital Heating & Air Blog

Here’s What a Heat Pump Defrost Cycle Looks Like


Winter is not far away, and it is time for you to brush up on your heat pump defrost controls before the time comes. When winter starts, man heat pumps require going through a defrost cycle to make sure that it can efficiently provide you with warm air indoors. The problem is that many homeowners are not clear on this aspect of their heat pumps when they get them installed.

We are going to discuss the process of the heat pump defrost cycle to help you understand. If you face any problems with the defrost cycle, you can schedule our heat pump services in Indianapolis, IN, to come and take a look.

The Heat Pump Defrost Cycle

When the heat pump switches to heating mode and the temperature gets colder, the moisture can freeze on the heat exchanger unit. The defrost cycle kicks in to get rid of the ice accumulated on the heat exchanger. It needs to get rid of the ice to make sure your heat pump can warm up your home efficiently. Here is an overview of the process:

  1. The defrost sensor detects when the coil temperature is cold enough to cause ice to form on the heat exchanger. The defrost sensor is typically mounted on a tube of the condenser, and it must be closed. Once it is closed, the control board begins saving the accumulated run time of the processor.
  2. As the accumulated run time meets the necessary level selected by the control board, the defrost sensor begins to work.
  3. The defrost sensor applies electricity to an electric strip that releases heat. It then energizes the reversing valve to switch the mode from heating to cooling, and then it de-energizes the condenser fan relay.
  4. The system is now effectively defrosting. The condenser heats up quickly because the fan motor is off, melting the frost. The electric strip controls the air being cooled by the evaporator.
  5. The defrost continues until the defrost sensor opens. It indicates to the defrost control that the coil is warm enough and doesn’t detect frost.

Is Your Defrost Cycle Working?

Several issues can lead to the defrost cycle on your heat pump being unable to remove the frost from the heat exchanger. If this ever happens, you should check the defrost sensor. It is an open switch that closes automatically when the temperature falls. If it does not work, you can remove the power from the condenser, remove the sensor, and examine it.

If you do not know what you are doing, you can hurt yourself or damage the heat pump unit. That is why we recommend calling in the professionals to take care of it for you. If you ever face any problems with your heat pump, getting a professional to take a look can guarantee you effective results.

Schedule Service with Vital Heating & Air Today. Your Comfort is Vital!

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