boiler shut down

[beanheadsteve]

Hi
we had a gw35ci combi boiler fitted about 5 yrs ago, now it has shut itself down because of high pressure ie:- 4.5 bar .
i have read the forum for ideas but no joy,the expansion vessel seems ok with no water coming out when checked on valve. i removed and made sure no deposits were in the flex to the expansion vessel, and also replaced the pressure sensor , theres nothing from the prv alls dry , any ideas please . thxs
ps , it is showing 4.5 bar when system is drained too

 

[gas4you]

I don't think it has shut down because of high pressure, more lilely there is no water/pressure in it and the pressure gauge is stuck, or blocked with crud.

You need to fit a new pressure gauge and re-fill system and bleed it.