3 Possible Causes of Heat Pump Short Cycling


Heat pumps are becoming more popular thanks to their energy efficiency and ability to both heat and cool. Short cycling is an issue that heat pumps sometimes face and is characterized by early shutdowns during heating or cooling cycles. Here are three possible causes of heat pump short cycling to help you understand this common issue.

1. Low Refrigerant

Like air conditioners and refrigerators, heat pumps rely on fluid refrigerant to transfer heat. In hot weather, heat pumps use refrigerant to draw heat out of your home and expel it outside. Unlike air conditioners, heat pumps can reverse this cycle and bring outdoor heat into your home in the winter.

Refrigerant is foundational to heat pump operation, and a drop in refrigerant levels can easily disrupt heating and cooling cycles. When refrigerant is low, your pump's heat transfer capacity is lower, and it may shut off before it finishes cooling your home. An HVAC technician can test the refrigerant charge in your heat pump and identify any leaks that may be causing the refrigerant to dissipate.

2. Failing Electronics

Heat pumps start up and shut down at the command of the HVAC thermostat. Unfortunately, this means that a faulty thermostat will impact the entire system. Short cycling sometimes originates from an electrical short or corrosion inside the thermostat that throws off its temperature reading.

Your heat pump also contains a circuit board called the control board that manages the compressor, fan, and other components inside the appliance. Like a failing thermostat, a faulty control board can have an unpredictable effect on your heat pump's operation and cycle times.

3.  Poor Insulation

One common cause of heat pump short cycling has nothing to do with the pump itself. When an HVAC system is sized for a home, the calculations assume that the house is insulated to an acceptable standard. As insulation degrades over time, your house will gradually lose more heated and cooled air. At a certain point, this starts to interfere with your heat pump's cycles.

Your heat pump may be short cycling due to damaged wall and attic insulation, or drafty windows and doors. Multiple small defects in your home's thermal envelope can add up until the temperature on the thermostat doesn't reflect the actual temperature in your house. If your heat pump seems to be in working order, a home insulation inspection could be the next step.  

If short cycling is becoming a serious issue with your heat pump, the causes listed above may be contributing to the problem. For the quickest resolution, call in an HVAC professional to track down the cause of your heat pump short cycling.


30 September 2022

Shopping For A New HVAC System

After my sister moved into my house with me, she started complaining about the temperature. I had never really thought about it before, or maybe I was just used to it, but my house was pretty cold. She told me that she didn't think the furnace was working properly, so I started checking things out on my own. Sure enough, my furnace seemed to be having some serious problems. I started looking for a replacement, and I was able to find a great furnace for much less than what I initially thought I would need to spend. I wanted to make this blog for anyone out there who might need to shop for a new HVAC system. Check out these great articles for information you might need.