Combi boiler leak

[earthakitten]

I have a slight water leak when DHW is used. The leak is coming from the push rod of the Pressure Differential Valve of Potterton Performa 24.
Is it likely to be a damaged diaphragm causing the problem?
I would be grateful for advice.
Thank you

[gasman]

No it is more likley to be the O-Ring inside the brass nut that the push rod protrudes from but if the diaphragm has not been changed for at least three years then you may aswell change it at the same time as renewing the brass nut that comes with the O-Ring built into it.

[earthakitten]

Many thanks Gasman for the information. I have just ordered a diaphragm. They said that they don't do a repair kit . Is it possible to change the 'built in' O ring?
Thank you once again.

[gucciman]

where did you order the spare part from as most manufacturers do a repair kit for their valves.

[earthakitten]

The local supplier claimed that Potterton don't supply repair kits, so I fitted a new valve (�75).
Thanks gucciman and gasman for your time.