Separate normal operation from a new sound
Air movement, gentle fan changes, refrigerant movement and outdoor defrost operation can create normal sounds. The manufacturer manual may describe these. A new rattle, grinding, scraping, loud buzzing or repeated clicking deserves attention.
Record a short video from a safe distance if the sound is intermittent. Note whether it begins at start-up, continues throughout operation, happens only in heating mode or comes from the indoor unit, outdoor unit, pipework or condensate pump.
Possible sources of unusual noise
Loose panels, vibration against a surface, debris near an outdoor unit, a worn fan component or a condensate pump can create distinct noises. Control and electrical faults may also cause buzzing or repeated attempts to start.
Do not remove guards, put hands near fans or tighten parts inside operating equipment. A technician can isolate the source, check fixings and clearances, and test moving and electrical components safely.
Know when to switch it off
Stop the affected unit if the noise is harsh, worsening or accompanied by a burning smell, smoke, repeated tripping, visible damage or a fan that appears obstructed. Isolate it only where the normal controls can be used safely.
Top Local carries out fault finding across Kent and the South East. The model number, video, operating mode and timing of the sound help us understand what should be checked first.