Vokera compact pressure rising after filling expans. Vessel

[mikeyw]

Ive recently re-pressured my expansion vessel to stop the bolier losing pressure after some great advice on here to 17.5psi (1.2bar). The boiler is showing 1.5 on the front so all good.

However when I turn the heating on the pressure quickly rises to 3bar and stays there until I switch off. I took the psi of the expansion vessel and it was 42.5 when the heating is on.

My assumption is 1.2 is too high as a starting pressure on the expansion vessel ?....is 0.8 more realistic ?

Tia,
Mike

 

[mikeyw]

Just checked the manual - the EV needs 0.8 not 1.2 !

Sure that'll sort it

 

[ianmcd]

First of all you MUST have a drain from the heating system open when you re-pressurise the expansion vessel there is NO other way this can be done, if it still rises after this it is probably a blocked communication hose

 

[Gasinayr]

Braided pipe connecting expansion vessel to boiler blocked. Disconnect pipe and clear. good luck, drain boiler and release pressure from ex vessel before disconnecting pipe or you will get a mud bath