Why is My Air Conditioner Making a Weird Noise?

If strange noises are coming from your air conditioner, it’s a sure sign that your HVAC unit has a broken component. How do you know which one it is?  

In today’s post, Air Authority, serving Cincinnati, Ohio, explains the different HVAC noises and pitches and what they can mean in terms of repairs. 

1. Squealing 

Squealing is a sign of high internal pressure, a dangerous operating condition that you should fix immediately for your safety and that of your HVAC. You’ll hear the sound within 10 to 15 seconds after an AC unit is powered. 

There are other reasons for hearing this noise, like a loose fan belt, which connects the fan to the motor, or dry fan motor bearings (rubbing metal to metal). 

Remember this: 

Newer AC units don’t use a belt system; they use bearings. But if your AC system is old, that belt that connects the blower to the condenser fan motor has seen a lot of wear n’ tear. If it slips off, you’ll hear a high-pitched squealing noise. 

For modern AC units, if you hear grinding or squealing noises, your motor likely needs to be replaced.  

2. Banging 

Often caused by loose parts. There’s likely a loose part outside or inside the compressor, like the piston pin or connector rod. 

3. Clicking 

When a clicking noise repeats throughout a cooling cycle, it’s probably due to an electrical issue with a relay switch or capacitor in the compressor. Clicking can often be the sound of a worn-out thermostat that needs to be replaced. 

4. Clanking 

Clanking noises also indicate loose parts jostling around. It’s also likely that the outdoor or indoor condenser fan blade is not being held firmly in place.

If it’s unbalanced, fan blades strike other components, damaging them and lowering your cooling results. 

5. Hissing 

Hissing is indicative of a refrigerant leak. Cracks in the refrigerant piping let the fluid escape into the system. A lot of pressure gets generated within the closed system since there’s nowhere for the refrigerant to escape.  

This generates a hissing noise which eventually becomes a high-pitched squealing. 

Sometimes hissing sounds are normal. The thermostatic expansion valve helps relieve all of that built-up refrigerant pressure, letting off a faint “hiss” sound. You’ll hear it indoors. It’s nothing to worry about. 

6. Buzzing

Buzzing noises from your air conditioner indicate a malfunction caused by a refrigerant leak, missing or loose parts, or a malfunctioning compressor. 

If your unit becomes lopsided or unbalanced, tilting to one side, the compressor loses balance and starts making a buzzing sound when on. 

Fix the Noise by Scheduling Professional AC Repair in Cincinnati

If you experience problems with your AC unit, Air Authority’s HVAC specialists can get the job done right the first time. Our team offers accurate diagnosis and professional, friendly service for a competitive price. Give us a call: 513-229-0789.