Is Your Air Conditioner Making Funny Noises? Find Out Why!

Homeowners hear strange air conditioner noises in their home.

Congratulations! Your old air conditioner has almost survived the summer.

Hamilton, Ontario, experienced some intense heat waves over the past few months. And we’re relieved to hear that your AC didn’t completely conk out on you during the worst of it.

But it’s not through the woods yet!

In classic Canadian fashion, summer and fall have confused their weather again. Leaving us with chilly mornings and sweltering afternoons.

Just another day in a typical Ontario summer!

But while your AC may have survived thus far, it’s no doubt feeling tired, worn out and neglected.

In fact, if your system is over 10 years old, it’s probably spending most of its time whining and complaining as it grinds out cool air each day.

Have you begun hearing strange noises coming from your AC unit?

It’s not uncommon for old, outdated air conditioners to get cranky. Or, in their case, legitimately whiney!

So as you prepare to settle in for the last bout of summer heat, you may want to start listening in for any of these air conditioning sounds.

While most of these sounds simply mean you need to schedule AC repair, others may point to something more serious.

(Psssst, don’t forget to read to the end of this article o hear about our End-of-Season Blowout Sale – happening now!)

8 Sounds Your Air Conditioner Makes When It’s Trying To Tell You Something

Last month, we talked about yucky air conditioner smells – namely how to identify and get rid of them.

But in this article, we’re switching senses!

Instead of using our noses to track down AC warning signs, we’re using our ears!

While most air conditioners aren’t typically silent, they should never be disruptive.

So if you’re hearing abnormal sounds from your AC unit, it might be trying to tell you something…

Below are 8 warning sounds your air conditioner could be communicating with you – LISTEN UP!


You might want to check your refrigerant levels if whistling sounds are coming from your air conditioner.

That high-pitched whistling usually means one thing – a refrigerant leak has developed!

And this leak, if not taken care of, can become dangerous to your cooling system and your family’s health.

As soon as you detect a refrigerant leak in your home, here’s what you should do:

Open all your windows and doors to help ventilate your home. This ventilation helps dilute the chemical leak as you move on to the next step of the process – calling our team for Emergency AC repair!


Hearing a “hmm” sound coming from your air conditioner? This is typically due to a defective relay switch – the element used to start your outdoor condenser.

As you can probably imagine, a malfunctioning relay switch means your air conditioner won’t turn on. This means you’ll be out of luck getting any heat until it’s fixed!

But wait!

Because this is an electrical issue, only a licensed technician should service it.

AKA, this is definitely not a DIY fix.

Contact our team today! We’ll have one of our qualified technicians out to fix the issue as soon as possible!

Note: Don’t leave this till the last minute to fix! Electrical issues can cause further damage to your air conditioner, leading to some hefty repair bills.


If you hear a whirring sound, often mirroring the sound of a helicopter, the problem is usually mechanical. Our technicians can typically narrow it down to one of two things:

  1. A problem with the indoor blower, or
  2. A problem with the outdoor unit.

Depending on what the problem is, you can typically fix it without calling in a professional.

But if it does happen to be a mechanical issue, be sure to call Shipton’s for a quick AC repair visit!


No, this is not the sound of teeth chattering. It’s still too hot out for that!

If you hear chattering sounds in your home, there are a couple of potential culprits.

Several of these you can fix on your own by,

  • Checking for loose screws.
  • Changing the air filter.
  • Tightening loose bolts.
  • Cleaning coils.

Others can be a little more intense – like an ongoing breakdown!

If your air conditioner is quite old, it could be deteriorating as we speak. In which case, that chattering noise you hear is actually loose parts getting knocked around in the system.

If this is the case, your air conditioner might be planning its retirement. Or, in other words, telling you that you need a new air conditioner – pronto!


The buzzing culprit is a little harder to nail down, as it can mean any number of things:

  • A loose fan motor
  • Out-of-balance fan blades
  • Dirty condenser coils
  • An old air filter
  • Loose parts

Most of these issues are easily avoided with annual Preventative Maintenance. But if you’re already hearing the sounds? You’ll need to call for AC repair.


If your air conditioner is hissing at you (not figuratively speaking), there are 3 potential causes:

  1. There’s a leak in your air conditioner.
  2. Your AC has the wrong type of air filter.
  3. There’s an expansion valve that’s malfunctioning.

Each of these issues requires an HVAC professional.


You may hear a clicking sound at the start or end of your cooling cycle, which is normal.

But if the clicking sound never stops, the likely cause is a broken or malfunctioning thermostat.

Thankfully, thermostats are not pricey. And it only takes a short time for your HVAC technician to replace it with a new one!


The sound of bubbling in your AC typically means there’s excess moisture in the unit.

The condensate drain line in your AC system carries excess moisture away from your home. But if this line becomes blocked, moisture gets trapped inside – causing that bubbling sound.

Inspecting the drain line for blockage is something you can do on your own. However, if the problem requires further repairing, the best call to make is to your certified Shipton’s technician.

Take Advantage Of Our End-of-Year Blowout Sale!

Is your AC past the point of no return? Take advantage of our End-of-Year Blowout Sale!

For one month only, you can SAVE $2,400 on our high-quality Furnace and A/C Combo Units!

This two-in-one system operates your heating and cooling at peak efficiency – providing your home with maximum comfort all year round!

With this dual system, you can save on:

  • Installation costs
  • Maintenance costs and
  • Operation costs!

Get More HVAC Tips From The Experts At Shipton’s Heating and Cooling!

At Shipton’s Heating and Cooling, we love giving you all the tips and tricks you need to keep your home running smoothly. If you have questions or want further information about anything we discussed here, give us a call!

Is this your first time reading our Shiptons’ HVAC blog? If so, we encourage you to browse some of our recent articles! We talk all about HVAC to help improve your home efficiency and comfort.

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