Heat Pump Noise Reduction | Five Ways to Make It Quiet

As an HVAC technician, I meet a lot of homeowners complaining about a noisy heat pump. Not only can the sounds disrupt your sleep, but they can also make it challenging to have peace of mind at home.

As such, heat pump noise reduction becomes essential as soon as the problem starts.

Ductless air conditioners are designed to operate efficiently and quietly. Therefore, any unsettling noises coming from the heat pump could mean there is a problem with the unit.

Heat Pump Noise Reduction (Troubleshoot and Make It Quiet)

1. Tighten loose parts

If you are a fan of DIY units, the chances are that you installed your ductless unit by yourself. This could mean you are familiar with some of the basic ins and outs of the unit and can fix any minor problems by yourself.

One common problem that could cause your heat pump to produce loud vibrations, clanking sounds, or metal banging is the loosening of parts.

This is especially so when the rattles or loud vibrations grow with time. Such a sound could also indicate that the fan is somehow out of alignment.

A fan can shift out of position due to a loose part. In addition, you might hear a clanking if debris such as leaves and sticks interfere with a moving part in the unit.

The sound can also result from a loose belt. The buildup of ice is another culprit that can cause the sound of metal hitting another.

This kind of noise often indicates that the fan blades are hitting an obstruction. Therefore, you should immediately shut off the unit as soon as you hear that metal-banging sound to save the blades, fan, or motor from damage.

A severe obstruction can cause the blades to break and fly off, damaging other components in the process.

Before putting your tools to work, take a moment to confirm what kind of noise you are hearing and where it is originating. This may involve sitting and listening to the appliance run through several cycles.

Once you locate where the sound originates, you can then tighten any loose parts and see if it solves the problem. Always remember to shut down the unit at the panel before commencing any repair work.

2. Clean out fan blades or replace them altogether

We have mentioned that debris can interfere with the fan and cause clanking sounds. Also, the buildup of ice can block or damage the fan and mortar. In addition, accumulated dirt can be another reason your fan and blades wobble or flutter.

If you see any of these things in the unit, it is best to clean them out right away and then switch on the heat pump to see if the sound is gone.

The aim is to make sure the blades are not damaged and the fan spins freely. In case of damage, you may want to replace the fan altogether.

Nearly every leading AC brand now has fans with quiet motors, so consider asking your vendor for recommendations.

3. Install compressor sound blanket wrap

Part of the process of diagnosing the noise problem will involve simply eye-balling the unit. In addition, you will be inspecting the heat pump for any visible evidence of a leak, damage, or a worn belt.

And, you may also use a level to check if the unit is in proper horizontal alignment. If none of these is the problem, your compressor might be old and causing excess noisy vibrations.

As long as it still functions properly, you won’t have to replace it. Instead, consider installing a sound reduction wrap over and around the compressor to dampen the sounds.

The wraps are made from noise-reduction material and fit snugly around compressors. They can reduce the noise by up to 40 percent.

Installing the wrap is a simple process. However, if you don’t feel confident doing it yourself, you may want to have an expert do it for you.

4. Install anti-vibration pads and vibration dampeners

The other solution for excessive compressor vibration-related noise is to use vibration dampeners. These anti-vibration pads or dampeners should attach to the bolts securing the compressor and help diminish vibrational noise.

This process is an easy and effective DIY solution if you are comfortable with tools. Still, you may call a technician if you prefer to discuss the issue with a repair company instead.

5. Have a technician replace the heat pump motor or fix any coolant leaks

There are some sounds you cannot correctly fix by yourself. These include noises associated with coolant leaks, low refrigerant, or refrigerant in the compressor.

If your unit has any of these issues, it may be time to call for heating, ventilation, and air conditioning service.

The professionals will have the required expertise and equipment to diagnose the extent of the issue and find the best solution for it.  

Why Your Heat Pump Might Be Making Loud Noises

There are various reasons an air conditioner may be louder. Although we have mentioned some of them already, here is a quick look at the common culprits and the type of noise they produce.

  • Loose parts: vibrating, rattling, and buzzing sounds
  • Heat pump not leveled: causes loud vibrations at start-up and shut-down, and swoosh sound when defrosting.
  • Unbalanced fans: vibrating, squeaking, rattling, or metallic clipping noises
  • Refrigerant problems: pinging, gurgling, popping, rattling, or buzzing, sounds
  • Motor problem: groaning or screeching noise
  • Compressor contactor problem: hissing, whining, or whistling
  • Electrical issues: clicking, snapping, or loud humming
  • Failing solenoids or valves: humming or clicking sounds
  • Ice: rattling, clicking, or vibrating noise
  • Debris: clicking or rattling sounds
  • Clogged drain: gurgling or bubbling noises
  • Rodents or birds: clicking or whirring

Now that you know how to diagnose and repair some of the common problems that might cause your heat pump to be louder than usual, you should be able to address an issue before it gets worse.

Let us know if you have any additional tips to suggest or comments to share in the comments section. 

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Jesse Pinkman is a passionate HVAC professional writer who grew up repairing any home appliance on which he could lay his hands. He is responsible for ensuring that every article we publish is SPOT ON. When he's not in the office, he enjoys hiking, watching football, and spending time with his family.