Worcester 28cdi Hot Water Problems

[GRZ]

Hello All,

I'm wondering if anyone can shed any light on this one?

The problem with my boiler is when i call for hot water (usually shower) it lasts for a minute or two then makes a clunk in which the pressure jumps by about .5Bar then settles out. The pump remains on but the gas and the burner switch off?!?

I've read a few things which suggest it could be the heat exchanger slugged up??

Cheers
G

 

[boilerdoktor]

is it the same at the taps ?

 

[GRZ]

Sorry should have added more detail there. Yea it is, happens at any hot water outlet in the house.

Central seems to be OK although not run for sufficient time as I have a few rads off at the moment for various work.