Is Sound an Issue in an HVAC Unit?

Is Sound an Issue in an HVAC Unit
Fri, 08/09/2019 - 9:00am / By christina

Is Sound an Issue in an HVAC Unit?

Newer HVAC units tend to run quietly. Older versions may emit sounds when the system starts up or when it's running, and it’s considered quite normal. However, if the noise is loud enough to interrupt you from binge-watching your latest TV shows, the problem may be more serious. If your AC unit is communicating through a series of hissing and whistles, it may be the right time to call an HVAC professional for immediate examination and rectification. Here are common sounds the technician may deduce.


Screeching epitomizes the noise produced when a metal grinds hard on another. Screeching noises could emanate from the blower motor that indicates motor bearing hitches or a defective belt. If the belt is faulty, an HVAC technician will replace it immediately. Belts aren’t expensive repairs. In the case a belt breaks before replacement, it affects the blower’s mobility. Also, the noise could be a lubrication problem. You may decide to lubricate the motor yourself with the right oil.

Loud rattling and banging noises

These sounds indicate that the HVAC system has some defective, broken, or disconnected pieces. It calls for the skills of an HVAC professional to examine the problem and seek an immediate remedy. Rattling sounds often mean that the blower assembly has certain loose components. The technician should tighten or replace the parts before the worst dawns. In the case of loud banging sounds when the motor is running, turn the system off. Thumping and clanking sounds could mean that the motor mounts are loose. The blower may also have fallen out of proper alignment. All these sounds demand special attention from a qualified technician for proper diagnosis.

Repeated clicking noises

It’s normal for your AC unit to emit steady clicking sounds when turning the system on or off. Most likely if you notice clicking noises emanating from the outside sections of the units when running the system, it could mean a small obstruction in the fan. You could try identifying the obstacles and clearing the way for seamless fan movement. If the clicking noise comes up when trying to turn the system on, it could be a sign of an electrical problem. The thermostat, capacitor, or compressor could also be faulty.

Popping sounds

Popping sounds are likely to recur when the metal parts in your AC system contract and expand due to changing temperatures. Popping sounds may be normal, but if they become steady, they could be irritating. Your technician may recommend installing an insulator to muffle the level of noise when the AC system is running.

Unsettling sounds indicate problems within the AC system. You could consider turning off the system as a precaution and call in an HVAC professional to inspect the unit thoroughly. Immediate remedies and inspections by a qualified technician could prevent costly repairs and replacements. If you notice any of these disturbing noises, contact us at Command Service Center.


Need to request a service appointment? Contact Command Service Center at (847) 558-7780 or use our online form to get started today!