Boiler has started making a strange sort of low vibration/whistling sound this evening. I say boiler, but the noise remains when the boiler is switched off, so it’s a noise coming from the general direction of boiler and related pipework. It disappears when you turn the hot tap on, but remains if the heating is on.

It stops every now and then but then starts quietly and builds up and gets noisier.

Any ideas?

bad juju.
system noise can be all sorts of things.. if it aint broke or waking the kids live with it.. we did a job recently where eon had refused to work on a noisy system until a power flush and pipe work re routing were completed £800 of work done they came back, and promptly walked away as it ‘needed ‘ a new boiler. we changed the diverter valve for £70 plus parts and cured the problem
if you must get a couple of people in and ask thier opinions start with the cheapest solution, there are now chemicals available to ‘silence’ your noisy systems for about 17 quid.. start with that..

It’s noisy when it’s off, i.e. completely off at the wall, no power, it’s quiet when it’s working! The noise is easily audible in the next room.

Anyway, tracked down the problem I think. Something round the intake for the hot water is not working as it should. If I close the tap for the intake the noise stops.

Boiler and related pipework is all less than a year old. Need to make enquiries as it’s all under warranty still, but not sure if that covers this bit or just the boiler itself.