Why is my air conditioner making strange noises?

What is the normal noise level for an AC?

The first thing to understand about air conditioning units is that they will all make some level of noise. Think quiet, not silent.

However, if your air conditioner is making strange noises and disturbing your sleep, something’s not right.

Here are the sounds you can expect from an efficiently running air conditioning unit:

• Sweeping sound of the fan as air blows through the vents
• Soft background hum
• Alerts for temperature changes
• Occasionally, soft clicking or popping when switching on and off

Top tip: Most air conditioning units list the noise level in decibels (dB). You should expect noise levels to range from 30 to 60-plus dB. The lower the decibels, the better!

Some air conditioning units go one step further and feature sleep modes. This handy function automatically turns off the air conditioner once the room reaches the right temperature to reduce the noise while you’re sleeping.

What does a bad AC sound like?

Abnormal sounds shouldn’t be ignored, as they often indicate that your AC unit needs to be repaired by a professional air conditioning engineer.

Sounds not to overlook include:

• Rattling
• Repetitive pops or clicking
• Hissing
• Significant buzzing or banging

Why is my air conditioner making noise?

This could be down to a few reasons, including:

• Quality – the more you invest in the air con unit, the quieter the model will be
• Installation ­– if the unit has been poorly installed, parts may have come lose
• Style of the unit – is it portable or wall-mounted? This can have a bearing on how much noise it’s making
• Age of AC unit – it could be a sign of wear and tear, and that it’s time to invest in a new unit
• Cleanliness – dust building up in the fans can start to create noise. It could be overdue a clean or a professional service

How to fix a noisy air conditioner?

Start by cleaning the fan and air filter yourself. This will help remove any dust and debris build-up, which could be a reason behind your noisy AC unit.

Just follow these simple steps:

1. Shut off the unit ­
2. Remove the vent cover – you might need to unscrew the vent cover to do this or use the cover release lever
3. Clean the cover and fan
4. Hoover out the filter
5. Wash the filter in soapy water
6. Dry it thoroughly
7. Replace the filter and cover it securely

If this doesn’t make a difference, your air conditioner most likely needs a professional service or a part repairing or replacing.

Remember – you’re dealing with electrics here, so don’t attempt to do this yourself. This is one job best left to the professionals.

Along with providing a professional service, an air con engineer may suggest the following:

• Replacement parts – Your air conditioning unit could be noisy because the compressor or capacitor needs replacing
• Repair loose parts – If a part has come loose, the extra stress on the other parts could be causing the noise. An air conditioning expert is best placed to diagnose this

Which brings us to…

How to find a quality air con engineer

Find a reputable tradesperson near you to investigate why your AC unit is so loud with these three simple steps:

• Use a professional directory

Make things simple by searching with a professional directory (like Checkatrade!). We’re so confident in the quality of the trades on Checkatrade that if you book through us, we guarantee their work up to £1,000. Guaranteed for 12 months – Eligibility criteria and T&Cs apply.

Contact or pay a trade through Checkatrade and you’re covered by our 12-month guarantee of up to £1,000*

* Eligibility and T&Cs apply

• Read online reviews

A review from a previous customer is the greatest testament to a tradesperson’s professionalism. At Checkatrade, we check all online reviews to ensure they’re from real people and that trades meet our high standards.

We check the reviews on Checkatrade are from real people, and that trades meet our high standards.

• Compare quotes

Get at least three quotes from reputable air con engineers. That way, you can be sure you’re getting the best tradesperson and price for the job. Search your postcode to get started.

How much does it cost to repair an air conditioner?

To help you budget, a home air conditioning service usually costs around £70 - £120 per unit.

Meanwhile, monthly air con maintenance agreement prices start at around £40+ per month.

You can learn more about the costs involved by reading our home air con service cost guide.

Key takeaways

• Don’t ignore abnormal noises from your AC unit ­– hire a professional engineer to investigate the cause
• Remember to book an annual service for your AC unit – as the saying goes, prevention is better than cure!
• If you need to buy a new AC unit, look out for models with the lowest decibel range and quiet modes

FAQs

Which is the most common source of abnormal noises in an air conditioner?

The AC unit’s compressor can often be the culprit. The compressor controls the refrigerant gas, which generates a lot of pressure and can cause vibrations and abnormal noises if it’s damaged. Don’t worry – you’re not expected to know where the compressor is to check if it’s damaged. A professional air con engineer can help with that.

Should I turn off my AC if it’s making a noise?

That depends. If your air conditioning unit is making a significant buzzing or banging noise, switch it off immediately. It might be a sign of an electrical malfunction – which could be a fire risk.

If it’s occasional popping, clicking, or rattling noises, it could be a loose part. So, while you may choose to continue using the unit temporarily, you’ll want to book a service in as soon as possible. Ignoring the issue could lead to further damage and a hefty repair bill.