Heat Pump Makes Loud Noise When Turning Off – Is This Ok?

Have you ever heard your heat pump produce a loud noise once you turned it off? We are certain that it made you nervous and think something is wrong with your unit. Since we want to help you with this matter, we conducted thorough research for answers.

It is common for your heat pump to produce noises at various points throughout its operation. This is  noticeable during a shutdown, which is a time in the system when quite a few things occur. So, this situation is okay.

Please read on if you want a more detailed explanation about this matter. Doing so might also answer some of your additional questions. So, let's delve into the details!

A male hand turns off air-conditioning system, Heat Pump Makes Loud Noise When Turning Off - Is This Ok?

Why Does My Heat Pump Produce A Loud Noise When Turning Off?

Immediately after you switch off the appliance, the pressures in the refrigerant begin to equalize. It causes the heat pump to make certain noises for a short period. Also, if you turn off the outside unit of your compressor, there is a possibility you could also hear a back-pedaling sound.

Outdoor air conditioning and heat pump units

Both noises should be acceptable; however, your heat pump may produce a few other clamors throughout the cutoff process that may signal a problem.

Why Is My Indoor Heat Pump Loud?

Air conditioning in the apartment on the wal

There is something wrong with your heat pump if you hear a noise like someone slamming a door in your duct vents. Below are possible reasons why your heat pump is making a loud noise:

1. Air Filter Crashing Into The Grille

If the location of your return vents is in your ceiling, you may run into this problem. You can tell when the unit is off because the filter "drops" from where it was pulled up against the top of the duct box. This situation is not normal, suggesting your filter is full of dirt and debris or excessively stringent.

Check the MERV rating and change the filter if it gets too dirty. It's essential.

Remember that if the ducts are too narrow, they will pull the filter into the vents. Changing the ductwork is your only option in this situation.

2. The Ducts Are Constantly Growing And Shrinking In Size

Temperature and pressure variations have a considerable effect on sheet metal ducts, causing them to swell and shrink. However, if the ducts are an adequate size and designed for the airflow through the system, this won't occur.

3. There Is A Fan Issue

The blower wheel may rub up against the heat pump. However, it is more likely that the fan's mounts will become less secure. If this occurs, the fan will collide with the unit as it slows down. It's best to call an HVAC professional for help, as this situation needs immediate action.

Why Is My Outdoor Heat Pump Loud?

Outdoor unit of a high efficiency air conditioner or heat pump

If you are outside and hear a sound like something has smacked the wall, this is most likely because of:

1. The Spring Of The Compressor Has Damage

A compressor is a closed casing containing many pieces that are liable for pumping refrigerant to and from the indoor unit.

The vast majority of the compressor parts, such as the pump that circulates the refrigerant, are what the springs hold. However, these supports are susceptible to deterioration or even complete failure.

Since the internal parts of the compressor will lose motion as soon as the heat pump shuts off, they will bang up against the housing. And if that's the case, it'll cost a small lot to change the entire compressor.

The noise does not necessarily indicate that the component is about to fail. Therefore, you may wish to disregard it if you can.

2. The Fan Is Banging Into The System

Similarly, the outdoor fan's blades may also dislodge. Once the heat pump quits working, the fan will crash into other parts of the unit.

You may only need to adjust a few bolts. But if the problem is more severe, it may require you to replace the entire fan.

What Does A Poor Heat Pump Sound Like?

If you notice and hear one of the sounds below, your heat pump might have a problem. Take a look!

1. Sound of Metals Clacking Together

Noises that sound like metal scraping on metal are almost certainly because of the fan blades colliding with an obstruction. To resolve it, we suggest stopping the heat pump operation first so that you can inspect it afterward.

If the fan blades are making a strange noise, it could be because they are striking an object that got stuck in the machine. Maybe the fan is rubbing against a part of the device. In some cases, the blades might cause a rupture in the refrigerant tube.

In any circumstance, the best action is to turn off the machine. It can harm the fan, the motor, or whatever equipment element the blades are touching if you ignore the noise.

2. Noises Resembling Shaking Or Vibrations

When shopping for a new heat pump, inquire about any possible rattling or vibration during operation. On the other hand, if your heat pump has never produced such noise, there has undoubtedly been a shift in the system. It might be because of:

  • Too much pressure in the pipes for the refrigerant
  • The metal cover panels are not tight enough
  • There might be some components of the air handler that are not adequately tight
  • The noise you're hearing might be from the ducting

If you want to lessen the rattling noise your heat pump produces, you can place rubber mats underneath your unit.

3. Buzzing, Grinding, Or Gurgling Sounds

One possible reason is a lack of refrigerant. Plus, if your unit's motor bearings are unclean, it may begin generating horrible screeching noises.

While a slight buzzing noise from coils or contactors is normal, a more noticeable noise level is not.

How To Stop Heat Pump From Making Noise?

Two air source heat pumps installed on the exterior of a modern house

Even if you turn the heat pump off, you'll still hear some noise because of its build. But there are specific strategies you can use to lessen the system's background noise, and they are:

1. Use Vibration Isolation Damper Mounts

The compressor will tremble occasionally, but this is pretty normal. Vibration, however, has the potential to become far more troublesome than any noise problem.

Fortunately, vibration isolation damper mounts are commercially available, and you can attach them to the compressor's mounting bolts. And nothing about the unit's efficiency or effectiveness will change, but the volume level will drop dramatically.

Check out these vibration isolator mounts on Amazon.

2. Use Compressor Sound Blanket Wraps

An HVAC specialist may place a sound blanket wrap around your compressor, which significantly reduces the noise it produces, muffling unwanted sounds.

If you've noticed that your once silent unit is making more noise as it ages, a sound blanket wrap may be the answer you're looking for.

Check out this compressor sound blanket on Amazon.

3. Utilize A Noise-Absorbing Base

This piece of advice is easy to understand. If you put your heat pump on a particular base, you can significantly reduce its noise output. And a rubber mat can help with this.

Check out this noise absorbing pad on Amazon.

4. Move The Heat Pump To Another Location

Placing your heat pump in a specific location can make a big difference in making your home cozy and comfortable.

For instance, it would be best to place the outdoor unit far away from windows.

Protecting the outside unit from high winds, which can cause defrosting problems and could force the system to operate at total capacity much more frequently, is an extra step you can take to go the extra mile. A hedge or a fence would work well for this purpose.

5. Replace The Unit

It is crucial to keep in mind that the typical lifespan of a heat pump is between 10 and 15 years. If your unit has recently started generating loud noises and is close to the end of its lifecycle, it would be more beneficial to invest in a new heat pump that is more energy-efficient and silent.

What's more, the EPA suggests it would be best to replace your heat pump when it reaches over 10 years.

Tips For Your Heat Pumps

Air conditioning and heating unit for a residential house

  • Adjust the temperature on your thermostat to only one level. Continually adjusting might increase utility expenses, particularly during the winter months.
  • If you choose to use your thermostat as a form of setback, it would be best not to extend the setbacks to twice daily.
  • It would be best that you should not set the thermostat lower than 65 degrees Fahrenheit during the heating season.
  • During the winter season, you should regularly inspect the outside heat pump for any signs of excessive ice or snow buildup on or around the heat pump, especially after a storm.
  • Remove any ice accumulation in the outdoor unit. After that, modify the thermostat and set it to the emergency heat position.
  • If you have already removed ice and snow from the device, reset the thermostat to the standard setting. And if it begins to ice again, contact an HVAC professional.
  • Do not place the outside unit in a location where a leaking gutter could harm it.
  • Raise your heat pumps between 4 to 8 inches from the ground to avoid ice and snow from accumulating on the coils.

Check out this Honeywell thermostat on Amazon.


If you think you are taking care of your heat pump properly, then it shouldn't worry you when you hear something from it when turning it off.

However, if it produces strange noises that you think are bad and not normal, it would be best to ask for the help of an HVAC professional immediately.

Thanks for reading! If you want to read further, you can check these additional posts below:

Heat Pump Not Keeping Up – What To Do?

Heat Pump Freezing Up In Winter – What To Do?

Share this article

Leave a Reply

Your email address will not be published. Required fields are marked *