Potterton performa 24 combi leaking

[jren]

Hi Everyone
I have the above boiler that is leaking from the central heating diff valve where the microswitch is attached.
I have searched the threads but most deal with the front diverter leaking. This is leaking from the top nut on where the microswitch touches the top valve.
I have attached some photos which show what it should look like (above)and what it does look like.
My query is can I replace the top part or do I need to replace all of it.
Is it likely to be the inside part many thanks..

 

[Agile]

Well that is an example of a boiler user failing to have the boiler repaired for a long time.

Bit like a car driver running on a flat tyre !

Once it gets like that a simple job can become far more difficult if screws will not come out.

Normally a fairly simple job.

In your case it could be a lot harder.

Tony