combine boiler banging noise, but ...

[daxu]

Hi,
I have this combi boiler, it starts to give me banging noise (randomly not all the time).

I had an engineer in and he said the boiler is ok and can't find where the noise from.

Later I found that when the banging noise is on, if I turn on the hot water tap,
the noise just go. If I turn the hot water tap off, the noise come back again.

Could this be a water pressure issue or something?

Many Thanks

 

[daxu]

can anyone help?

Many Thanks

 

[45yearsagasman]

Call him back and demonstrate exactly what is happening.

 

[ALEC1]

is the water pressure correct

 

[daxu]

The banging nose stops when I put the hot water on.
It is so strange and annoying.

 

[ambrosia]

water hammer,

cured by pipe work clipping, lowering water pressue, or new stop cock