Worcester 28i Combi Boiler Knocking sound

[libbo2003]

Hi just noticed in the last couple of days my 28i combi boiler has a knocking sound every couple of minutes when idle. The heating is coming on fine when required, and the hot water is also working fine. It has not been serviced for a few years now. Any ideas what it could be would be appreciated.

Water Pressure is fine on the gauge just over 1Bar.

Thanks guys.

 

[Agile]

Its difficult to imagine a cause fpr knocking whjen idle.

Why have you not had it serviced?

Tony

 

[bazdaman]

OP not had it serviced as would rather say money than get the gas appliances checked for safety and performance then when it goes wrong will slate the manufacturer for making a **** boiler when regular servicing would poss of eliminated any problems!

 

[libbo2003]

Had boiler serviced, Engineer says the knocking sound is my mains water and nothing to do with the boiler. So checked my toilet ball-valve which looked like it was letting by. Plumber changed my ball-valve washer. but the knocking is still happening. it is seems something to do with the mains going to the boiler. The filling loop seems fine so can it be the Mains feeding the hot water side of the Boiler? No taps or the toilet are being used yet the boiler knocks once about every minute.

 

[bazdaman]

If no taps or water being used then it's unlikely the main does it do it if stop tap is off? It's very hard to diagnose a noise even if the customer is explaining face to face sometimes unless the engineer hears it it's a nightmare!

 

[libbo2003]

If no taps or water being used then it's unlikely the main does it do it if stop tap is off? It's very hard to diagnose a noise even if the customer is explaining face to face sometimes unless the engineer hears it it's a nightmare!

Hi thanks for you response, stop cock of no sound,
really strange.......plumber says mains pipe is knocking somewhere near the boiler,But nothing on the mains is open but the boiler makes one knocking sound every minute roughly.
Cant tell if there is a leak on my mains because no meter outside to see if its spinning when all taps ect are closed.

 

[TCCHeating]

Are you on a shared mains? Terraced houses normally? It could be sound being transferred down the pipe from somewhere else. Otherwise you could try Ghostbusters

 

[libbo2003]

Are you on a shared mains? Terraced houses normally? It could be sound being transferred down the pipe from somewhere else. Otherwise you could try Ghostbusters

Hi all the houses are on their own mains connections, but it might be from next door!! She has gone away on holiday this morning and it might have stopped??? Hopefully it will stop until she gets back and then we can find out if that is the fault!!
Once again thank you for your help guys.