Pressure gauge vibrating like mad

[mylocalplumber]

Got a Keston heat only boiler to 2 UFH manifolds off 2 2 port valves and a 2 port to the 3rd zone. Hot water off unvented but apparently the pressure gauge is going berserk. Any ideas? Seems to happen when all off so could it be a bypass issue? Don't know reading on guage yet till she sends a pic.

 

[Chalked]

Hi
Are you Gas safe? As this will probably be the filling loop passing. Your ok changing that. But not the safety valve. This may need changing too and is inside the boiler.

 

[Magnaman]

As above, had a faulty filling loop I changed, had been going so long had damaged the prv. You need GSR to replace this.

 

[PlumbBobBob]

Mylocalplumber are you gas safe? if so send an image of your GS card to gas man via PM and you will be admitted to the inner sanctum of the gas section.