Loud banging from boiler when hw is on

[Paulcs34]

Hi we moved into a house 4 years ago, we never used the boiler for hw as it used to make a terrible banging sound and the flow pipe also bangs and what sound like gushing water. It seems to bang when the hw is turned on and when the ch and hw are on together and the ch goes off. The CH works fine when on by itself. Now we want to get it fixed as it costs to much to heat the hw using the hw cylinder. It is a worcester bosch 40 CDI conventional boiler, I had a plumber come round, he replaced the 3 way valve but still the banging continues any ideas would be welcomed.

Thanks Paul

 

[Agile]

It sounds as if there is a limited flow when HW is selected.

Check for enough water in the system and that the hot water circuit is not blocked.

I always wonder why people wait four years before getting something fixed. The extra cost of electric heating will have probably been five times the cost of the repair.

Tony

 

[Paulcs34]

Hi Thank you for your response.

Finally got fixed yesterday, it was a problem with the pipe work but basically the flow out of the cylinder was piped to the flow out of the bolier so the water was colliding now its been piped correctly no more banging.