What These 4 Noises Mean When You Turn Your Air Conditioner On

When people mention they have a noisy HVAC system, they usually are referring to their air conditioner. If your bedroom is by the outside air conditioning unit, you might have noticed it squealing or screeching while you try to sleep. 

Air conditioners make a variety of different noises – some are good, and some aren’t. Before summer moves in this season, understanding these noises can help you determine if your cooling equipment is working well, and when you should bring in a technician to keep everything running smoothly. 

The most common noises include:

What These 4 Noises Mean When You Turn Your Air Conditioner On

Squealing noise

Squealing noises most often come from the lower or compressor motor. It’s usually a sign of parts wearing down and in need of replacement. While you might hear it at the beginning of the season when it starts up for the first time, if you continue to hear it, checking with a professional will help you get a better feel for what needs replacing. It’s a good indicator that you’ll be replacing the entire cooling system soon. 

Humming noise

A humming noise almost always indicates your fan is dirty or in need of replacement. If you haven’t had the filter cleaned at the start of the season, calling in a professional will ensure your cooling system is ready for the summer months. They will replace the filter, inspect the various parts, clean off dirty or corroded equipment, and make recommendations based on their findings. If you leave a humming noise unchecked, it could cause a disruption when you need it most. 

Thumping noise

This is an indicator of a compressor problem, or a bad part on the outdoor unit. Start by checking the outside unit to determine if branches or other landscaping items have damaged the equipment in any way. 

Whistling noise

A whistling sound usually indicates there’s a build-up of dust somewhere in the system. If you hear it when the AC unit is operating, it’s a sign of lint build-up in the system, which is restricting air flow where it’s needed. If you notice it when the system is off, there is an obstruction or damage somewhere within the ductwork. 

Before we get into the heat of the summer, schedule your inspection today. 

You can count on Quality First

From start to finish, we go the extra mile for our customers.

Simple, friendly scheduling

We're here to help. Get an appointment time that fits your busy schedule.

Service experts, not salespeople

Our goal is to get your problem fixed, at the budget that works for you.

Know your technician

We will send a photo of your tech before the appointment along with live GPS tracking updates.
DENVER METRO (720) 772-5081
CASTLE ROCK (720) 325-1371

Helping people is our passion


We believe in giving back

As a family business owned by Colorado locals, we are committed to our community. That's why we support and provide free services to charities and nonprofits across the Front Range.