Potterton Performa boiler pressure at 3.00 bar when cold

I have a potterton perform 30 boiler which when off is read 3 bar and dripping from prv. I have tried bleeding a radiator which dropped pressure by .5 bar, but went immedialey back up. Cant get a plumber out until Wednesday to look at it is it safe to continue using the hot water.

Guy came out last week and said problem was pressure expansion vessel which was at 1.00 and he pumped it to 3 and turned boiler tempeture down which seems to make it worse as original problem was pressure rising rapidy when heating switched on but went back to 1 bar when off.

Help

Is the filling loop disconnected?
If not disconnect(after ensuring valves are off), and see what happens.
If the presure still goes up,then the most likely thing is a holed plate heat exchanger.
Graham

i would check your filling loop is not passing

Trouble is the filling loop is on so tight I can't get it off.

try turning off your mains and check if pressure rises