Heat pump noise problems such as buzzing, grinding, clicking, loud, gurgling, rattling, high-pitch, thumping, rumbling, hissing, whooshing, banging, humming, and howling are just some of the sound problems that will be covered here and explained, including the reasons for easy troubleshooting.
During the normal air-to-air heat pump operation, either cooling or heating, it is normal to hear a soothing, humming, or purring sound.
Anything unusual, especially abnormal noise during operation, should be the first sign of problems and would require a professional to diagnose the problem.
There could be several reasons why your heat pump is making a noise. Here are some of the most common causes:
During the wintertime, 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 colder weather, the heat pump can operate at different speeds, producing a higher noise level than when it is warmer.
This is usually related to the fan hitting something while spinning; ice, wire, or metal element. The problem should be immediately taken care of to avoid any damage to the fan blades.
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.
The clanking noise indicates that some of the elements inside the heat pump are loose and need to be checked and tightened. 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 the noise doesn’t exceed the level defined in the specification sheet, there is nothing that can be troubleshot; it is not considered the problem.
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.
A buzzing sound could indicate an electrical issue within the heat pump. This could be caused by a loose wire, a malfunctioning contactor, or a failing capacitor.
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.
A hissing sound is caused by the discharge of humidified or ventilated air.
Vibration is also normal but can be reduced by installing rubber isolation pads under the heat pump.
It's important to note that heat pumps can make some noise when they are operating normally.
If you are experiencing a loud noise coming from your heat pump, it is recommended that you turn off the unit and contact a professional HVAC technician to diagnose and repair the issue. Continuing to run a heat pump that is making a loud noise could lead to further damage and potentially costly repairs.