Why Are There Strange Noises Coming from Your Air Conditioner?

Man covering his ears

When it’s absolutely scorching outside, there’s nothing quite like sitting and relaxing in the quiet cool of an air conditioned home.

Of course, if your air conditioner makes a terrible racket each time it turns on, it’s a sure sign that air conditioner repairs from Advantage AirTech ClimateCare are needed.

After all, air conditioners should be relatively soundless.

With that in mind, here are common noises you don’t want to hear coming from your air conditioner and what’s causing them.

Screaming noise

  • WHAT’S GOING ON: A piercing, shrill screaming (like a kettle boiling over) or hissing noise that lasts for about 15 seconds when the AC kicks in. The noise eventually stops, but the air conditioner may repeatedly turn itself off and on.
  • WHAT’S CAUSING IT: The compressor, more than likely. Higher-than-normal pressure is accumulating somewhere in the AC. As a result, the compressor begins to scream loudly.
  • WHAT SHOULD YOU DO? Turn off the unit and book air conditioner repair. High-pressure inside the system is quite dangerous

Squealing noise

Fan belts

  • WHAT’S GOING ON: As the air conditioner (or even heater or fan, for that matter) is running, a squealing noise is coming from inside the unit. It comes and it goes, but it’s always there.
  • WHAT’S CAUSING IT: Look at the fan belt. It could be tattered or askew. The belt connects the fan to the motor. Through regular wear-and-tear, the belt wears out and/or becomes misaligned. As a result, your AC begins to squeal.
  • WHAT SHOULD YOU DO: You can keep using the AC if you like. Just remember, the belt might completely break. If that happens, you’ve got zero cool air. Get it fixed sooner rather than later.

Knocking noise

  • WHAT’S GOING ON: During operation, there’s a knock or bang coming from the air conditioner. But, when you switch the thermostat to “FAN”, the noise goes away.
  • WHAT’S CAUSING IT: The fan itself is banging into something, like a stick or other obstruction. Another possibility is that the fan has come loose from its mount. In that case, it’s hitting the housing/casing as it’s rotating.
  • WHAT SHOULD YOU DO: Turn it off ASAP. Leaving it to run will end up leading to bigger – and more expensive – problems. Contact us and we’ll fix it for you.

Screeching noise

  • WHAT’S GOING ON: As soon as the AC kicks in, an abrasive and awful metal-on-metal screeching noise appears. The sound does not go away until you turn the air conditioner off.
  • WHAT’S CAUSING IT: A classic sign of the fan motor bearings wearing out. If the bearings are shot, the fan motor will need to be replaced too.
  • WHAT SHOULD YOU DO: If the temperature is unbearably hot, keep running it. But you’ll need to schedule a service call and get it repaired ASAP.

Refrigerant leak detectorBubbling noise

  • WHAT’S GOING ON: Your AC sounds like its gurgling water as it’s running. However, you aren’t quite sure where that noise is coming from.
  • WHAT’S CAUSING IT: Chances are, there’s a refrigerant leak somewhere. Another possibility is there’s something happening inside the condensate drain line itself.
  • WHAT SHOULD YOU DO: If you keep running it, you probably won’t make matters worse. But make certain you place a trap under the drain line. If you think it’s a refrigerant leak instead, get it looked at by a professional.

Clicking during operation

  • WHAT’S GOING ON: As your unit runs, there’s a continuous clicking noise. Over time, they get faster and more persistent as the air conditioner remains on.
  • WHAT’S CAUSING IT: Did you ever put hockey cards in the spokes of a bike wheel? Something similar is happening to the fan unit.
  • WHAT SHOULD YOU DO: There’s a blockage in there somewhere. You’ll need to contact a technician to remove it without damaging the fan.

Clicking at start-up

Noisy AC? Contact us now

A noisy air conditioner is bad enough.

But a noisy air conditioner which doesn’t actually blow cool air? That’s downright awful.

If your air conditioner is making the sounds listed in this blog (or other noises which have you worried), don’t wait and hope they just “go away on their own.”

Contact us for a service call.

Wherever you live in Ajax, Pickering, Oshawa, or surrounding areas, we’ll come to you and get your AC running properly – and quietly.

Contact us