Inherent leaking diaphram valves?

[combiner]

Re: Flow valve in Combi Boiler

A diaphram valve within the combi boiler is constantly leaking. I understand that some minute clearance is required for the operating pin to move (in order to operate the switch) but obviously the water seeps through this clearance.
Is this just an inherent fault or can the leak be stop without restricting the movement of the operating pin??

Thanking you in advance.

 

[taydo]

there should be no leaks anywhere inherited or paid for

it would help if you mentioned the boiler make and model

but i would say you probably need a new diaghram or diverter