Heat Pump Noise
Cause and Solution

Heat pump noise problems such as buzzing, grinding, clicking, loud, gurgling, rattling, high-pitch, thumping, rumbling, hissing, whooshing, banging, humming, howling are just some of the sound problems that will be covered here and explained, including the reasons for an easy troubleshooting.

During the normal heat pump operation, either cooling or heating, it is normal to hear a soothing, humming or purr sound. Anything unusual, especially an abnormal noise during operation, should be the first sign of problems and would require a professional to diagnose the problem.

Troubleshooting heat pump noise problems

Whoosh sound

During the winter time, when the outside temperatures are very low (freezing) and ice starts to build-up on the outdoor unit, the heat pump will automatically melt the ice or snow build-up utilizing the defrost cycle. The result of this action is not only the fog or vapor rising, but the specific “whoosh” sound, which is nothing unusual. During the colder weather, the heat pump which can operate at different speeds, producing the higher noise level than when it is warmer.

Metal sound

This is usually related to the fan, hitting something while spinning; ice, wire, metal element… and should be immediately taken care of to avoid any damages on the fan blades.

Clicking sound

Clicking sound is also normal; it takes place when you turn the heat pump on for the first time after a long time of inactivity. If you hear it more often, the problem might be with the start capacitor and when it breaks the heat pump won’t run. The clicking sound can also be coming from the refrigerant control valve and other electric components.

Clanking noise

Clanking noise indicates that some of the elements inside the heat pump are loose and need to be checked and tighten. Investigate the moveable parts such as the fan belt which gets loose due to wear.

The changes in the noise level are normal, and as long as noise doesn’t exceeds the level defined in the specification sheet, there is nothing that can be troubleshoot, it is not considered as the problem.

Grinding noise

Grinding noise means that there is a problem with the compressor or fan motor, actually bearings. If the motor lacks lubrication or there is dirt inside start looking for a new motor.

Buzzing sound

Grinding noise means that there is a problem with the compressor or fan motor, actually bearings. If the motor lacks lubrication or there is dirt inside start looking for a new motor.

Bubbling sound

A bubbling sound usually occurs when the outdoor air enters the drain hose, especially when the house or apartment is completely closed and the wind is strong.

Hissing sound

 A hissing sound is caused by the discharge of humidified or ventilated air.

Vibration is also normal but can be reduce by installing the rubber isolation pads under the heat pump.

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