Informational Guide

How Often Should a Heat Pump Cycle On & Off?

When the heat pump turns on and off constantly, it’s going to run inefficiently and be a burden to you. Learn what to do with our complete guide.

by Josh M

The heat pump is an essential part of your home’s heating and cooling systems. You need it to run efficiently. Otherwise, you’re looking at higher power bills each month. When the heat pump turns on and off constantly, it’s going to run inefficiently and be a burden to you.

Are you wondering how often should a heat pump cycle on and off? You’ll want to keep reading this guide for the answer!

White Thermostat at 63 Degrees

The heat pump is similar to an air conditioner system, although it heats as well. It’s normal for the pump to cycle on and off. Your heat pump should stay on for about 10 to 15 minutes before turning off. When it runs too often, this is known as “short cycling”- it can’t keep your home at the right temperature in this state.

You’re experiencing short cycling if the system shuts down for a short amount of time, then starts back up. The issue can happen whether you’re using cooling or heating. Short cycling is a sign that something is wrong, wastes electricity, runs inefficiently, and causes the lifespan of your appliance to lower drastically.

If your heat pump is running properly, it should cycle two or three times in an hour while running for 10 to 15 minutes at a time.

Why Exactly Do Heat Pumps Cycle On & Off Frequently?

There are many different reasons why heat pumps cycle on and off frequently. There is likely an internal issue with your machine. Before the appliance starts raising your power bills, you’ll want to check for the following problems.

Air Filter Clogs

Always make sure to check the air filter first. This problem occurs frequently and is likely to happen when you don’t change the air filter. Debris and dust clog the filter, restrict the movement of air, and lower the efficiency of the heat pump.

Luckily, it’s a very easy problem to fix. Simply remove the filter, then clean it or replace it with a new one. You will want to check on your clean filter often so it doesn’t clog like the first one.

Leaky Refrigerant

When it’s hot outside, your heat pump uses refrigerant to cool down your home by taking heat outside. In the cold months, the heat pump does the opposite by bringing heat into the home.

Leaky systems can make it harder for the refrigerant to perform this heat transfer. When that happens, your machine is going to short cycle. You’ll need a professional to make the repairs for you.

Oversized Unit

If you have an oversized unit, you’ll want to replace it. The machine heats and cools the space too fast, causing it to shut down before reaching its target temperature. When that happens, the unit continues cycling without anything to show for it.

Thermostat Error

Sometimes, the thermostat is giving you the wrong reading. It could be due to where you have it set up. If it’s in a drafty or sunny area, the thermometer will pick up temperatures that are inaccurate for the rest of the home.

The thermostat might also have faulty wiring. When that happens, it won’t communicate well with the rest of the heat pump system.

Why Is the Frequent Cycle Of Heat Pumps a Problem?

When your unit has too frequent cycles, its performance will suffer. If the heat pump cycles too often, it’s turning on and off constantly. When the pump starts up or turns off, it’s using more power than at any other part of its process. It takes a lot of energy to accomplish this- it’s more efficient when it runs for longer.

You can expect to see this reflected in your monthly energy bills. The more the heat pump short cycles, the higher the bills will be. The parts of the machine are also put under more stress and could break sooner. Finally, you’ll feel uncomfortable since the room isn’t getting to its target temperature.

Heat Pump Behind the House

Troubleshooting Tips for Heat Pumps

The following are the most common causes of short cycling in heat pumps and how to troubleshoot them.

Unit Cycles On & Off Quickly

For this problem, start by checking the air filter. You’ll want to clean the filter or replace it. Allow the unit to run and watch it carefully. More often than not, this fixes the problem! However, if the unit is still short cycling, you’ll want to take these steps:

  • Repair any leaks you find
  • Move the thermostat
  • Call a professional to determine if the unit is oversized

If you can’t determine the cause, some of the parts may be worn out. You should have someone come check it out for you.

Fan On Heat Pump Won’t Shut Off

The fan should turn off with the rest of the system. The most common causes for this problem include:

  • Faulty wiring
  • Bad thermostats
  • Stuck relays

These issues can’t be fixed with a DIY project. Instead, you’ll want an electrician to repair the wiring for you. Before you call anyone, make sure to check if the thermometer is just getting a bad reading due to its location. Do this by moving it to a new spot in the room.

Compressor Cycles On & Off

This problem could be due to the low-pressure control switch having issues. This happens when the refrigerant in the system leaks and goes below a certain point. You’ll want to replace the parts and the refrigerant, which is something an expert should do for you.

People Also Ask (FAQ)

Can a bad thermostat cause short cycling?

Yes, when your thermostat can’t get an accurate reading, it will lead to short cycling. It can signal to the heat pump to turn off before the cycle is finished.

Why is my heat pump in defrost mode?

The unit goes into defrost mode when there’s ice on the outside of the heat pumps. Defrost mode removes the frost, so the machine can work as it was intended.

What is the defrost cycle on a heat pump?

When frost forms on the outside coils of the heat pump, it struggles to run. To counteract this, the machine runs a defrost cycle to remove the frost, helping it run more efficiently.

Is it bad for the heat pump to run all the time?

No, the heat pump is designed to run for long periods and does so efficiently. It’s usually only a bad sign when the unit cycles continuously, without much space between the cycles.

Conclusion

If your heat pump kicks on then off, you want to first check the air filter. Once you’ve dealt with any debris clogging the filter, you should have an easier time figuring out what the problem is. It’s best that your machine doesn’t short cycle since it’s much more expensive for you!

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.

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