April 5, 2021
Air Conditioner

Your air conditioner should make a humming sound when it’s operating normally. If it makes loud noises, it’s a sign something has gone wrong. The type of noise it’s making is helpful in figuring out what the problem is.


This sound comes from your outdoor AC unit’s electrical parts. You’ll often hear it when the air conditioner turns on or off. If you hear a clicking sound at other times, it’s a sign the controls are faulty.


A banging sound can indicate several things. The indoor blower may be unbalanced. It can also come from a loose piston pin, connecting rod, or crankshaft.

Brian's Heating & Cooling, Inc. in Madera, CA, can help when you hear odd sounds coming from your air conditioner. Since we have NATE-certified technicians, we can service all makes and models of air conditioners.


The blower fan motor will make a squealing sound if its belt or motor bearings are worn out. The sound can also come from the compressor if its motor is faulty.


If you hear a hissing sound when your air conditioner turns on, it’s a sign of a major problem. The sound will usually last about 10-15 minutes. The problem is that high pressure is building up in the compressor. You should turn your air conditioner off and not use it until it can be serviced by a technician.


The cause of a whistling sound is often a dirty filter. The filter has become clogged with dirt. You should replace the filter to solve this problem. Whistling can also occur if your ductwork is damaged.

Loud Humming

If your air conditioner is making an unusually loud humming sound, it’s probably being caused by the fan. It probably just needs to be tuned up by a technician, but loud humming can also be caused by a failing fan motor or bent fan blades.


Rattling is usually caused by twigs or pebbles in your outdoor AC unit. It can also mean there are some screws or bolts loose.

At Brian's Heating & Cooling, Inc., we can help you diagnose and fix any issues with your AC. We also repair, install, and tune up heating and cooling systems. Our other services include tankless water heaters, indoor air quality, duct cleaning, duct sealing, energy audits, ventilation, and ductless mini-splits. Please call to schedule an appointment.

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