Potterton Performa 28i - HW problems

[amd3766]

Hi

I've got a Potterton Performa 28i. The CH works fine, with a system pressure around 2 bar, but the supply of hot water is playing up. Pre-heating the water works, but the boiler then doesn't switch into hot water mode when a hot water tap is opened. I can only get hot water when
I open ALL the HW taps in the house, provided the boiler is operating
(for CH) at that time. I then close all the taps except for the the one
I actually need, and the HW keeps working.

I have checked the various filters and venturi, and they seem fine (ie not
clogged up).

Any suggestions ?

Thanks

 

[gas4you]

Replace the DHW diaphragm.

 

[amd3766]

I changed the diaphragm (which was punctured) and that fixed the problem. Thanks a lot ! most grateful for your advice.

 

[HP1961]

How much did the diaphram cost?

I have same problem and was looking for an on-line stockist - if you know one can you recommend please?

 

[ChrisR]

http://www.partscenter.co.uk/hrpc/default.html