Boiler bangs when switched off

[PaulST]

My Worcester-Bosch 28i Junior combi gives a bang when switching off any hot water tap and also when the central heating goes off. It's done this since it was installed. Any ideas on what is causing it and whether it is likely to cause further problems in the future? Thanks.

 

[corgiman]

sounds like the diverter valve to me.

is it still under warrantee?

 

[ChrisR]

Not having a good day, are you corgiman me ol mate? No DV.

WHat sort of bang, Paul? Mechanical clang in the pipes, boiling sort of lumpy bang from the boiler...?

 

[corgiman]

DOH



i was thinking of the cdi

(kicks himself up the jacksy)

 

[PaulST]

Apologies - got the model wrong. It was going to be the junior but then the vertical flue was 3.8 metres which is too long for the 28i junior so they had to install the 28Si which allows a flue of up to 4m. Someone suggested to me that it could be the flue pulsing given that it is so long (is that likely?), but to me it sounds like a muffled bang coming from within the boiler (definitely not the pipes clanging).