A Guide to HVAC Noises and Their Meaning

Let’s look at the various HVAC noises and what they might mean.

Loud Banging

A continuous banging noise coming from your AC unit can be a sign of the blower motor not operating smoothly, loose parts, a damaged connecting rod, or worn-out bearings. You should schedule AC repair as soon as you notice loud banging sounds coming from your AC unit because ignoring signs of AC trouble can lead to more expensive replacements.

Buzzing

When your HVAC unit is working efficiently and correctly, it should not produce any noise louder than a low hum. If your air conditioner is making a buzzing noise at the outdoor unit, chances are that something is wrong with your unit. A buzzing noise could indicate the following issues:

• Loose AC parts
• Compressor malfunction
• Refrigerant leak
• Capacitor breakdown
• Faulty motor
• A problem with your unit’s electrical setup
• Frozen evaporator coil
• Damaged isolation feet

If you hear a buzzing noise coming from your AC unit, turn it off for a few hours and then turn it on to see if the problem persists. If the buzzing noise persists even after giving your AC a break, call a professional HVAC company to inspect the unit and make repairs.

Screeching or Squealing

Is your AC producing a high-pitched screeching or squealing noise? This can be due to the following:

• The bearings on the condenser fan’s motor are worn down
• A malfunctioning blower and fan
• The belt connecting the motor to the blower may have slipped
• High pressure in the compressor unit

If you hear a squealing or screeching sound coming from your air conditioner, turn off the AC immediately and contact an HVAC professional as soon as you can.

Repeated Clicking

It’s normal if your HVAC unit makes clicking sounds when it turns on or shuts down. However, repeated clicking is a sign of a problem that needs to be investigated and fixed. Repeated clicking could be a sign of an electrical problem, a faulty connection between the compressor and the thermostat, an obstruction in the AC fans, a malfunctioning thermostat, and many other issues. You can fix an AC fan obstruction yourself by removing the outdoor unit cover and wiping the fans clean. For the other problems, you need to call a trusted HVAC company to help you with repairs.

Rattling

There are many reasons why your HVAC unit could be rattling. The common reasons include loose AC parts, a misaligned fan blade, an obstruction inside the outdoor unit, and a faulty motor. A rattling AC unit is indeed an annoying problem, but it can also be a sign of greater malfunctions that need to be checked by an HVAC professional.

Pulsating

A slow pulsating noise coming from your AC unit may not be anything to worry about, but if the noise is loud and rhythmic, you may have to call a nearby HVAC company and schedule AC repair. A pulsating noise may point to a loose fan blade or refrigerant lines getting in contact with the AC walls.

Need reliable and affordable AC repair? Call Absolute HVAC Service today!