What’s Causing Your Heat Pump to Shut Off Unexpectedly?

As a homeowner, you’re probably a constant user of your heat pump during the winter season because it’s convenient and efficient. But when it comes to residential AC and heating, it’s important that your unit’s heating and/or cooling is in sync with the temperature setting on your thermostat. If you notice that your unit is having a hard time maintaining the temperature set on your thermostat, this can be caused by a number of factors.

What’s Causing Your Heat Pump to Shut Off Unexpectedly?

If this issue isn’t addressed properly, it will lead to other internal errors such as turning on and off continuously, or short cycling, which can drive up your energy bill. If your heat pump short cycles frequently, this means it’s having trouble heating or cooling your home because the unit can’t maintain the set temperature. It’s shutting off and restarting too often, which isn’t very efficient for your home.

If you think you’re already having this problem with your HVAC unit, then you’ll need to have it checked out by a professional residential AC technician. To learn more about why your unit keeps shutting off prematurely, Above Air Inc. shares some insights here:

Short Cycling Issues

“Short cycling” is a phenomenon in which a heat pump shuts off too early in its heating or cooling cycle, before it’s able to reach the desired temperature. You’ll notice this when your afflicted heat pump turns on and off numerous times instead of maintaining a regular temperature.

Short cycling is an indication that your heat pump has internal issues that will wear it down faster. This will affect your comfort and also drain extra power, since a heat pump uses the most energy when it starts up. To prevent more costly repairs, it should be checked out by an HVAC repair technician as soon as possible.

The Causes of Short Cycling

A common cause of short cycling is thermostat issues. Normally, your thermostat is responsible for sensing the temperature in your home and turning the heat pump on and off when appropriate. When it’s not calibrated correctly, however, its heat anticipator inaccurately gauges the temperature and causes the heat pump to shut off prematurely in both heating and cooling modes before set temperatures are reached. If you’re not familiar with your unit, you can have your thermostat manually calibrated by trained technicians.

Your thermostat might also be installed in a poor location, such as by the vent or window, where it’s exposed to direct sunlight or drafts. This results in false readings that can also lead to short cycling. Another possibility is faulty wiring between your thermostat and heat pump.

In addition to the thermostat, other common causes may include:

Incorrect size

The heat pump in your home needs to be correctly sized for the space in which it will be installed. This is no DIY task, as it usually requires a professional to perform a thorough inspection of your home to determine the number of BTUs of heating and cooling necessary.

Normally, a properly-sized unit will only need to work half the time, or about 50 percent of its cooling/heating capacity. Of course, the actual usage of your heat pump will vary depending on factors such as fan speed and cooling coil cleanliness, but you’ll typically hear or see the compressor/condenser motor of your outdoor unit turn on for about ten minutes then remain off for about the same length of time. Basically, a 20-minute on-off cycle would be normal.

If you hire an inexperienced technician to do the installation, there’s a high probability that they’ll install a unit that’s incorrectly sized, which can be an expensive problem to fix. This will likely result in short cycling because your heat pump’s output will either be too powerful or too weak for the designated space. If it’s too big, it will rapidly reach the target temperature and shut off before finishing the heating cycle.

To ensure a professional inspection,

make sure to call experienced HVAC repair contractors instead. When you take advantage of our services, we’ll perform a heat load calculation (which is also called a manual J calculation) in the space where you want the heat pump to be installed. This calculation determines the optimal heat pump power output for precise heating and cooling.

Leaking refrigerant

Your heat pump’s air conditioning or air cooling function is completed through a process that relies on refrigerant. During the winter season, the refrigerant takes heat from the outdoors, where it’s pressurized, then releases it into your home.

If you have a refrigerant leak, your system will have a hard time transferring heat, as it won’t be able to complete a cycle and will eventually shut down. If you’re already seeing ice buildup on your outdoor heat pump, this usually means it has a refrigerant leak, so make sure to seek help from a professional technician as soon as possible.

Clogged air filter

Whether it’s a residential or commercial AC system, this type of problem is often caused by overheating, which is often the result of a clogged filter. Your heat pump’s air filter should be kept clean in order to prevent airborne contaminants from being sucked into the sensitive working parts of the system.

Over time, dust and debris will form on your filter. If you don’t change it regularly, the particles will restrict airflow and force your system to work harder to pump more air through the system. And because it’s no longer able to circulate the right amount of air to heat or cool your home, your unit will eventually overheat due to the workload and short cycle itself.

To prevent this from happening, be sure to check the air filter regularly, depending on the service intervals prescribed by your heat pump manufacturer. You should clean or replace the filter as needed. In extremely cold and hot seasons when heat pump usage levels are higher, checking air filters monthly is recommended.

When you’re looking for an excellent commercial AC technician, don’t hesitate to call Above Air Inc. You can reach us at (954) 833-6836 for Broward or (561) 488-0832 for Palm Beach. You can also fill out our convenient contact form to get started!