Baxi duo tec combi occasional noise

[searcher65]

The boiler is working correctly and has been recently serviced but at random times when it is not actually working it emits a loud knocking noise (just one )loud enough to make anyone in the kitchen jump. Anyone with any ideas ?

 

[mikeb]

Hmm, how long as the boiler been in?, normally the knocking noise would be air lock possibly, or full of gunge . so thats when its running you'd have the knocking through the pipes, then its adrain down and flush out the gunge and start again. how long is it off before iy makes the one noise?

 

[searcher65]

Boiler has been in just over 2 years it happens sometimes when it has just stopped running or it can be or half an hour or so later. It sounds like somebody knocking on the wall and it does it up to 6 times a day then some days it doesn't do it at all

 

[Gordon T]

Has it been serviced? If not, get someone in. They should find the problem easily enough.

 

[diamondgas]

Do you have ghosts? lol

Sounds like some sort of cooling down contraction noise. Does it happen when the boiler first comes on by any chance? Has it done it since installation? Had any pipe alterations recently or radiators off? Reason being you may have a pipe tight on a floorboard, something like that, giving expansion/contraction noise.

 

[mikeb]

yep i agree with daimondgas, a good gas guy should sort it, you need to be at the premises to find all the little nitty things that boilers do.