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4 Central Air Conditioner Noises You Should Never Ignore

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crazywomanGot a noisy air conditioner? The noise isn’t just annoying, it could also be a sign/symptom of a larger problem that can do costly harm to your air conditioner.

Even if your AC is cooling well right now, you should have a technician investigate your central air conditioner if you hear any of these 4 noises.

Note: Noises can come from 3 places in the air conditioning system:

  1. Inside evaporator unit
  2. Outside condenser unit
  3. Ductwork

In this article, we’ll focus on 4 dangerous noises from the outside condenser unit.

Hissing or bubbling noise

A hissing or bubbling noise can mean refrigerant is leaking out from a refrigerant line or coil. Refrigerant is needed for the AC to cool your home and is expensive to replace. So get this fixed ASAP.

You may hear this noise inside or outside your home because, for a split system, you have 2 refrigerant coils (one on the outside unit and one on the inside unit) and refrigerant lines that connect the 2 air conditioning units.

Buzzing noise

A loud buzzing noise (sounds like a loud vibrating electric toothbrush) points towards an electrical issue with any one of these electrical components:

  • Contactor relay switch— This is a low-voltage switch in the outside unit controlled by the thermostat that turns your outdoor unit on. It’s relatively inexpensive to replace.
  • Condenser fan motor— The condenser fan is the fan in the outside (condenser) unit. If the inside AC unit is still blowing air, but the outside fan isn’t turning as it should, then the motor may be worn out and failing.
  • Loose wiring at any component—The connections may be loose and making this noise.

If you hear this noise, turn off your AC and call a repair person ASAP.

Clanking and banging noises

The scary clanking/banging noise coming from your outside unit is most likely a loose part from inside the AC’s compressor. Some parts that could become loose include:

  • Connecting rod
  • Piston pin
  • Crankshaft

Unfortunately, compressors on most modern air conditioning systems are hermetically sealed (i.e. “airtight”). So the only “repair” is to replace this costly part.

Screaming noise

A very loud screaming sound usually means there’s high internal pressure inside the air conditioner’s compressor.

The compressor usually has a high pressure sensor that will shut your air conditioning system down if internal pressures get to a dangerous level.

But if the compressor continues to run and make the screaming noise, turn your air conditioner off immediately since this is a very dangerous situation.

Call an air conditioner repair contractor for help.

Need help?

If you live in New Jersey and need help figuring out what’s causing those air conditioner noises, contact Air Professionals online for help or call us directly at ​908-284-2422.

Air Professionals is a whole-home comfort company serving New Jersey homeowners. Contact us for more information on how we can help improve your home’s comfort.