Boiler overflow dripping

[Basker21]

the over flow to my boiler is dripping. I have had a new expansion vessel, PRV and filling loop fitted but it is till dripping. Anyone got any idea what it might be...obviously paid out quite a lot for it not to be fixed and don't want to pay anymore than necessary. Pressure is at 1.2 when cold and goes up to just over 2 when CH is on. Any help would be most appreciated.
Thanks claire

 

[jeff the gasman]

Did he just swap the innards of the PRV or the whole unit?
If the former, get him back.

 

[Basker21]

I believe it was the whole thing. This is the invoice x

 

[jeff the gasman]

Pressure gauge or PRV could be faulty. If it's the gauge it could be the plate heat exchanger passing.