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Why is My Ductless Mini-Split Making Strange Noises?

Ductless Mini-Split

Ductless mini-split systems in Smithsburg, MD, operate relatively quietly under normal conditions. While you may expect some sounds from your ductless mini-split, there are strange noises that you should never ignore.


A hissing or high-pitched sound from your ductless mini-split should raise concerns about the health of your equipment. The common cause of the noise is a refrigerant leak from loose valves or damaged coils. The refrigerant facilitates heat exchange that your system can’t function without.

Neglecting to schedule a repair may lead to the destruction of the compressor, resulting in the replacement of the entire system. Unfortunately, a refrigerant repair isn’t a DIY task as it requires professional handling for safety.


The air handlers in your mini-split systems contain a series of greased bearings. Over time, the bearings wear out and friction between them causes loud grinding noises. If you hear this sound, contact an HVAC service technician immediately before the air handlers burn out.


A rattling sound indicates loose or damaged metallic parts in the ductless mini-split. A routine maintenance check will help to avoid such noise. During the session, your HVAC service technician will tighten loose bolts and repair or replace broken parts.

Buzzing or Humming

Buzzing or humming sounds signal electrical malfunctions in the compressor. It implies your system is getting an odd number of amps due to a defective contactor relay switch. Sometimes, the sound could be due to the starting capacitor or a failing motor.

Resolving the issue requires expert knowledge to avoid further complications or damage to other components. Contact a trusted HVAC provider in Smithsburg, MD, for prompt and accurate ductless mini-split repair services.

Our certified service technicians can provide you with the best options for your ductless mini-split. Learn more about ductless heaters and air conditioners by requesting an appointment with Hagerstown Heating & Cooling today.

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