4 Reasons Why Heat Pump Turns On and Off Repeatedly

The heat pump is known for its efficiency, but they’re not without flaws. They are known to turn on and off, all on their own. This is an issue that heat pumps experience that will reduce their ability to warm your home and even cause a spike in your heating bill. So what exactly causes a heat pump to turn on and off repeatedly?

When a heat pump turns on and off repeatedly, this is called short-cycling. Short-cycling can be caused by a number of factors, including thermostat issues, inaccurately sized systems for a home, air filter clogs, and even refrigerant leaks! The long-term effect of this is inconsistent heating in the home and possibly even heat pump failure. 

When your heat pump is short-cycling, you may wonder if there is anything you can do. What exactly are the most probable issues? What can be done about them? When you know what these are, you are more capable of getting the best repair to keep your heat pump working at top capacity.

Top 4 Reasons Why Heat Pump Turns On And Off

While heat pumps are a complex mechanical system, there is a shortlist of reasons that it may be short-cycling.

This is great as a lot of HVAC problems are not as easily solvable. Not all of these issues are instantly rectifiable, so knowing which ones you can handle and which ones need immediate attention will save you time and money in the long run.

The top four reasons for heat pump issues are:

  1. Thermostat Issues
  2. Air filter clogs
  3. Refrigerant leaks
  4. Wrong size heat pump

1. Thermostat Issues

Your thermostat plays a huge role in the heating and cooling of your home. This little box does more than just let you interface with the heat pump.

It records data on temperature, humidity, and the general home environment to tell the heat pump when it’s needed and when things are fine. 

Honeywell thermostat

When your thermostat has issues, it can lead to issues with your heat pump! What kinds of issues can a thermostat have?

Poor placement can lead to it being unable to accurately record the in-house temperature. A short could have it not functioning. Even a small wiring or programming issue can lead to it sending conflicting demands to your heat pump.

Most thermostats come with a manual that can help you do some troubleshooting of your own before calling the experts in.

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Make sure to always keep the manual and review the information they have provided to see if a programming or wiring issue is taking place. 

If the issue is not in the manual or seems to be a bigger problem, contacting your local HVAC technician can have it fixed in no time flat.

They will be able to move or repair the thermostat to make sure it is reading correctly and relaying information to your heat pump sans issues. Once repaired, your heat pump should stop short cycling.

Read: Heat Pump Heats, But Does Not Cool

2. Air Filter Clogs

Dust, debris, and pollen are some of the biggest offenders when it comes to system issues. Whether it’s poor air quality due to clogged-up ductwork or a filled filter preventing airflow, these particles can usually be found at the scene of the crime.

Dirty HVAC filters replacement

That’s why it’s no surprise that they can have just as great an effect on your heat pump as well!

When you see your system beginning to struggle, the first thing to look at after your thermostat is your air filters. These should be changed regularly to prevent issues, but it’s not always the case. Air filters are usually in an out-of-the-way area that doesn’t immediately alert a homeowner to clean or replace it. 

If you pull the air filter out and it looks filled or clogged, it is time for a replacement. Doing so may be able to return your heat pump back to its best efficiency, allowing air to move within the home again.

Simply check the size, purchase, and replace. It is not tricky to accomplish and will be done before you know it.

How can you be sure to change out your air filter regularly? In order to prevent things like this from happening in the future, start a calendar to remind you to change your air filters in your home regularly.

Having an alert on your phone can also make it simple to remember that your air filters need to be changed. 

3. Refrigerant Leaks

If you never have a problem with refrigerant, you may remain unaware of it in your system. However, the refrigerant is key to how your complete HVAC system works to keep your home comfortable.

heat pump turns on and off - repair

Without it, your home will not be able to be cool during the summertime, and your HVAC won’t be able to get the precise temperature your home needs.

What does refrigerant do? When air is being pulled into your HVAC system or heat pump, it passes along coils where refrigerant removes heat from the air. This allows the system to adjust the temperature as needed so your home gets the comfort it requests. During the winter, it works to pressurize the air as it travels from the outside to the inside.

If you suspect a refrigerant leak, the first thing to do is a complete walk around your HVAC unit. Look for any ice on the system or pooling liquid.

It is important that you do not touch it. This may be refrigerant, which is a chemical. If you see ice or liquid, immediately contact your local HVAC technician for service. 

It cannot be stressed enough that if there is a refrigerant leak, you should have a professional handle it. Do not touch or get in close proximity to the fluid.

It is mostly colorless and odorless, but it can be toxic and harmful to the touch or if inhaled. Some manufacturers add a slight green tint to help you better identify it, but it’s best to just contact a professional asap. 

4. Wrong Size Heat Pump

Heat pumps come in many different sizes. This is to make sure the home always has a system designed to work for it. When purchasing or having a heat pump installed, bigger is not better.

Multiple sizes and styles of heat pumps

The thought is, “The bigger the system, the faster and less it will have to work,” right? This is not the case at all!

A larger system will actually be less efficient, drain more power, and work even more frequently than it should. That is why it is so important to get an HVAC system sized to your home.

With the right-sized heat pump, your home gets the warm air it needs and doesn’t have to experience high energy costs. 

If you suspect your system is the wrong size, the best thing to do is contact an HVAC technician. They can check the size against your home, identify the issue, and help you find and install a system that is correct.

Most heat pumps will have a rating that will correspond to specific house sizes or square footage, meaning they are optimal for those sizes of homes. 

While needing a new heat pump installation doesn’t sound like a great time, it will save you in the long run and prevent short-cycling.

You will immediately see better results in terms of heating and power consumption. Since your system won’t have to work as hard, it will be able to deliver quality heated air when needed the most. 

Getting Your Heat Pump Back to Its Best

When your heat pump turns on and off (short-cycling), the home may feel like it’s never going to get to the perfect temperature.

While sounds of your system kicking on and off repeatedly may not sound like a problem, it is a sign of your heat pump saying it needs help and service. Ignoring it can lead to high electric costs and even the possibility of failure.

Take a look at the things you can control, such as your thermostat and your air filters, first when you suspect short cycling.

These smaller issues may be the culprit, allowing you to fix them easily without much help. Keeping up with the maintenance of these systems will prevent future problems from arising.

If it is a bigger issue, like refrigerant leakage or a wrong-sized pump, you absolutely will need to contact your local HVAC technician for help.

Some of these issues can, in fact, be dangerous to those exposed to them, so it’s best to have a professional handle them. They are trained professionals who can get your system either repaired or replaced to restore your home’s comfort. 

With the right-sized system, your home can be comfortable all year round. To make sure your system is always at its best, keep an ear out for strange sounds such as short cycling from your system.

Consider regular HVAC system service at least twice a year for check-ups and warranty maintenance. That way, no matter what the weather throws your way, your HVAC is ready.

Read: Who Makes The Best Heat Pump System?