Odd Noises You Don’t Want to Hear From Your AC - Dowd HVAC

Odd Noises You Don’t Want to Hear From Your AC

The end of the summer is a stressful time for a home air conditioning system: all the work the AC has done cooling the house through sweltering hot months can catch up with it and trigger malfunctions. If you’re vigilant about your AC at the end of summer, you may catch warning signs of a need for AC repair in Hatboro, PA before the cooling system fails. The sooner you know to call our expert team to look into odd behavior from your AC, the better the outcome!

Weird noises from an air conditioner are major warning signs to watch (or listen) for. We’ve compiled a list of common “bad news” AC sounds below. When in doubt, call us to investigate and see what work will rescue your cooling system.


The vibrations of an air conditioner can cause parts to loosen after enough years. This is probably what you’re hearing when the AC begins to create a distinct rattling sound. On the less severe side, rattling could mean the door to the indoor air conditioner cabinet wasn’t latched fully. Test the door to see if this is the case before calling for professionals.

Grinding & Screeching

These sounds fall under the general category of “mechanical wear and tear” noise. What you’re likely hearing in both situations is a motor in bad shape. A mechanical screeching sound means the bearings in a motor are wearing down. If the bearings wear down completely, the friction on the parts of the motors will lead to it burning out. Grinding means the motor is already burning out. If you catch the screeching sound first, you can have technicians replace the bearings and protect the motor.

Continual Clicking

You can expect some clicking noises from the various electrical components in an air conditioner as it starts up; nothing to worry about there. When the clicking sounds become commonplace and you hear a swarm of them when the air conditioner starts its cooling cycle, you may have a “hard starting” AC. What’s that? It’s like a hard-starting engine in a car: the motors are pulling on too much power to overcome initial resistance. Technicians can fix this in several ways, depending on the situation: installing a hard start kit, replacing old capacitors, etc.

Hissing & Bubbling

These noises may seem like warnings of different problems. They actually point toward the same issue: leaking refrigerant. When refrigerant in high-pressure gaseous form starts to escape from small holes in the copper lines, it creates hissing. When refrigerant in low-pressure liquid form escapes, it creates bubbling. Leaking refrigerant jeopardizes the entire AC, so have our experts on the job right away.


The sound of metal striking metal often means a part is loose in the blower assembly, a bent fan blade is striking the casing, or the blower fan has become misaligned. We recommend shutting off the AC to stop any further damage, and then calling us ASAP.

Rely on Dowd Mechanical Heating & Air Conditioning for your AC repairs, no matter what they are. A Degree Above the Rest.

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