Why is my heat pump making a loud noise?

Heat pumps are generally quiet, so a new or louder noise usually means something has changed. Some sounds are normal, others are worth investigating. Here is how to tell the difference.

Normal sounds

A low hum, occasional whooshing during a defrost cycle, and the fan speeding up in cold weather are all normal. These come and go and are nothing to worry about.

Noises that signal a fault

Rattling, grinding, buzzing or a sudden loud vibration point to a problem, often a loose panel, a failing fan bearing or debris in the unit. Ignoring these can turn a small fix into a bigger repair.

What to do

Clear any obvious leaves or debris around the unit and check nothing is resting against it. If the noise continues, book an engineer. We diagnose the cause and restore quiet, efficient running.