Photograph of  This new compressor was placed directly against
a brick wall. One third of its condenser coil cooling ability was blocked. HVAC Noise Diagnosis & Cure
How to Evaluate Air Conditioner / Heat Pump Compressor, Air Handler, Ductwork Noises

  • POST a QUESTION or READ FAQs about air conditioning or heat pump system equipment or control or ductwork noises: cause, significance, cure

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Air conditioner or heat pump noise diagnosis & cure:

HVAC systems can produce a stunning range of noises many of which can help lead quickly to the trouble source and thus can help tell us what repair is needed.

This air conditioning repair article discusses the diagnosis and repair of air conditioning compressor noises which range in importance from normal (if annoying squeaks and squeals, to rattling loose bolts and hardware, to shrieking and howling or death-rattles that sometimes (not always) presage costly compressor damage indicating air conditioning compressor or A/C compressors at or near end of their life.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

A/C & Heat Pump System Noise Diagnosis & Repair Noises: How to Diagnose Air Conditioner Compressor, Fan, Refrigerant Piping, Ductwork Noises

Photograph of an old burned-out air conditioning compressor unitIn the A/C system noise diagnosis article below we discuss how we approach listening to and interpreting noises coming from an air conditioning or heat pump system.

Topics: how to diagnose & repair noises or sounds traced to HVAC systems including compressor/condenser units, air handler units, air conditioners, heat pumps, furnaces, ductwork, motors & controls. Recordings of HVAC system noises.

Categories of sound by HVAC system sound type & what the sound significes.

Article Series Contents

This article discusses how to diagnose & repair air conditioning compressor noises from the compressor/condenser, air handler, duct work, filters, or controls

If your air conditioning or heat pump system has lost its cooling capacity or won't start


See HOW to DETERMINE COOLING CAPACITY of air conditioning equipment if the system seems to be working but is inadequate to cool your building. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution.

First question in diagnosing HVAC system noises is where are the noises coming from?:

Second question in diagnosing air conditioner or heat pump noises & sounds: what does the noise sound like?

Air Handler & Ductwork Noise Diagnosis & Cure for HVAC Systems

How to Diagnose & Fix Noises at the Compressor/Condenser & Condenser Fan Unit

If you hear unusual noise at the air conditioning system, these compressor sounds could indicate the need for a simple service and adjustment requirement.

But air conditioner compressor noises might also mean that you face an upcoming costly repair involving replacement of the compressor itself. You should have the system checked promptly by an air conditioning service technician.

The following is a list of air conditioning compressor noises and what they may mean about the operation, condition, and remaining life of the cooling system equipment.

I have a National comfort Products CPO 2464-B unit which is an air conditioner and gas heating unit combined.

The unit is about 5 years old. The air conditioner had become increasingly noisy. I called the party that installed the unit. After spending $90.00 for a service call I was informed the the external coils were dirty, opening up the unit light was not visible thru the coils.

I was advised to use a garden hose and rinse the coils. I did not have that available so I turned the unit on and using a watering can, poured warm soapy water onto the coils. this was done several times. the unit now seems to work properly. I did not see this particular problem described on your website.

There may be other means of cleaning the coils but this was all I could think of. - C.A.P., Norristown PA

How to Diagnose Noises at a Split System Air Conditioner / Heat Pump Indoor Wall-Mounted Unit

Fujitsu has offered some helpful advice in troubleshooting noises that may be heard at the indoor wall-mounted air handler of a split system air conditioner or heat pump. What's particularly helpful is that Fujitsu points out that some noises that people worry about are actually normal and not an indication of trouble. Quoting [3]

Here are some other noise or sound diagnostic clues for split system air conditioners & heat pumps


Continue reading at NOISES, HVAC SOUND DESCRIPTIONS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see HVAC SYSTEM NOISE DIAGNOSIS FAQs - questions and answers posted originally on this page.

Or see these

HVAC Noise Diagnosis Articles

Or see this

List of Common HVAC Failures that Cause Noises

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