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Grinding, Squealing and Screeching: Interpreting the Noises Your HVAC Makes

If something is failing or going amiss with your HVAC unit, chances are, your HVAC unit is letting you know something is not quite right. However, most of the cues come in the form of sounds that many of us may overlook. If you hear your HVAC unit grinding, squealing, screeching or squeaking, it is letting you know it needs help. I was unaware of these cues and overlooked them. It ended up costing me a lot of money in repairs. I want to make sure that does not happen to other people, so I made this website. I hope you learn how to interpret the noises your HVAC unit is making so you can get it the repairs it needs before you incur a costly repair, or worse, permanently ruin your unit for good.

Grinding, Squealing and Screeching: Interpreting the Noises Your HVAC Makes

Reasons Your AC Is Smelling Like Smoke

by Billie Carlson

An AC does not have an internal engine; hence there is no reason why you should experience a smell like smoke. Therefore, when you notice an acrid smell from your cooling system, there is an underlying defect. Since the issue may escalate into a system breakdown, it is advisable to engage an AC repair technician to inspect your unit. They will establish the cause of the smell and fix it to prevent costly repair and replacements arising from secondary damage. The following are the reasons your unit is smelling like smoke.

Dust Accumulation

If you go for a long time without using your AC, dust may accumulate within the filters, ductwork, vents, and heating components. As a result, when you run the AC, the heat will burn the dust on the coils, producing a smoky smell. Although the smell should not persist, you should contact an AC expert if it fails to dissipate quickly. They will vacuum the air passages and replace the used-up filters for clean airflow.


When air filters clog with dust and debris, they may impede airflow into the system. This results in the compressor overworking to provide adequate cooling. Consequently, the motor will overheat and produce a smoke-like odor. In addition, the bearings may degrade due to constant function, causing a burning smell as they rub against each other. Thus, it is imperative to hire an AC professional to clean or replace your air filters, depending on whether they are washable or disposable. They will also oil the bearings and clear the area around your outdoor unit to prevent overheating.

Electrical Failure

If there is a short-circuit, electrical arc, or power surge, you may notice a smell like smoke from your unit. This results in the capacitor blowing, wires fraying, and tripping the circuit breaker. Whereas the electrical faults may arise from the connections wearing down, rodents and pests may interfere with wiring. Therefore, you should call a repair expert to reassemble your electrical connections, replace blown parts and fasten them securely for proper current flow.

Belt Driven-Motor Is Overheating

Older generation ACs will produce a smoky odor when the fan belt wears down and begin to overheat. This causes the belt to melt and emit a highly pungent smell of burning rubber. Thus, it is crucial to hire an AC repair contractor to replace your belt for the peak functionality of the blower compartment.

Smoke-like odors when operating your AC indicate defects that may cause a system breakdown. Therefore, you should schedule regular tune-ups with an AC repair specialist to ensure your cooling unit is in good working order. 

For more information about AC repair, contact a local professional.