The part(s) or condition(s) listed below for the symptom Heat pump is noisy or loud are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The condenser fan motor has bearings that can wear out over time. When the bearings are worn out, they make loud noise. To check the bearings, try rotating the condenser fan motor by hand. If the motor does not turn smoothly, replace it.
The fan motor has bearings that can wear out over time. When the bearings are worn out, they make loud noise. To check the bearings, try rotating the fan motor by hand. If the motor does not turn smoothly, replace it.
The fan blade on the condenser fan motor might be defective or loose. To check the fan blade, wiggle the fan motor shaft. If the motor shaft is loose, tighten or replace the set screw. If the condenser fan motor is still making noise, replace the fan blade.
The compressor pumps refrigerant through the heating and cooling system. When the compressor is wearing out, it generates more noise than usual. When this happens, it is not necessary to replace the compressor—compressors often last for years after they become noisy. However, if you would prefer to have a new compressor, you must have a licensed professional replace it.
If the outdoor unit is noisy, the grille or one of the panels may be loose and vibrating. Check for loose panels and tighten them as needed.
The furnace or air handler control board sends a low voltage signal to the contactor. When the contactor receives the signal from the control board, it closes the circuit, sending voltage to the outside unit components. If the contactor is wearing out, it may start buzzing or making loud vibrating noises. If the contactor is noisy when its energized, the component should be replaced.
Over time, debris can fall into the outdoor unit, causing a noise when the fan is running. Inspect the fan blade and the inside of the unit for any debris. Clean out the outdoor unit as needed.
