combi boiler bang noise when hw tap is opened

[kr5ai]

Hi I have a Heatline sargon combi boiler which I know is not the greatest boiler but has been ok for the last couple of years the problem I am having is;

When the CH is on and the HW tap is then opened there is a loud banging noise , the bang is only once and I can not tell If it just from the pipe or boiler and pipes.

If the CH is off and the HW tap is then opened there is not noise while the HW is running.

The cold tap doesn't have any fault.

Thanks any advice of what this could be would be great as unfortunatly it is out of all warranty periods.

Chris

kris

 

[Whitespirit66]

Vaillants had a similar problem recently. Sticky diverter valve.

 

[Agile]

Does it happen regardless of how the tap is turned on ( eg slowly ) ?

Is it a quarter turn tap?

Does it still happen if boiler has no power to it?

Tony

 

[bell824]

Vaillants had a similar problem recently. Sticky diverter valve.

Recently were have you been for the last three years?? Corrected along time ago.

 

[kr5ai]

Hi thanks for the replys

all the taps in my house are mixers taps

it only happens when the central heating is on and then I turn the hot water on

the bang happens even if I turn the hot tap on slowley

on the boiler once the hw tap has been opened there is a 30 second delay before the ch kicks in again during this period I can open and close the HW tap as many times as I like with out and banging but as soon as the CH comes back on and I put the HW tap on it bangs again.

thanks

 

[Whitespirit66]

Vaillants had a similar problem recently. Sticky diverter valve.

Recently were have you been for the last three years??

Three years?

Recently?

Are you having trouble with the meaning of the word 'recently'? (as well as being unable to spell the word 'where'. )

http://dictionary.cambridge.org/

Can you quantify recently?

Are you saying that no sticking diverters have been changed in the last 3 years?