Understanding common sounds and when to take action.
Heat pumps do make some noise — they contain a compressor and fan, similar to an air conditioning unit. However, some noises are normal while others can indicate a problem. Here’s a practical guide to help you understand what’s typical and what’s not.
A steady, low-level hum or whir from the outdoor unit is normal, especially when the compressor is running. This is the sound of the system working.
You may hear air being moved by the fan. This is completely normal and similar to the sound of a fridge or freezer compressor starting up.
Small clicking or ticking sounds when the heat pump turns on or off are usually normal and caused by the system switching components on and off.
These sounds are not normal and usually indicate a mechanical issue, such as loose parts, a problem with the compressor, or debris inside the unit. Get it checked by an engineer.
These sounds often point to issues with the fan motor or compressor. They should be investigated promptly as they can indicate a developing fault.
Some vibration is normal, but if it becomes loud or increases over time, it could be caused by loose fixings, unbalanced fan blades, or installation issues.
Make sure nothing is blocking the unit (leaves, debris, snow, etc.) and that the unit is level and securely mounted.
Note whether the noise happens when the system starts, stops, or runs continuously. This information is useful for an engineer.
If you’re worried about a noise, contact your installer or a qualified heat pump engineer. It’s better to get it checked than risk a bigger problem developing.
Use our Heat Pump Estimator to better understand what a well-performing system should look and sound like.
Use the Heat Pump Estimator