Vokera Linea 24 Combi Boiler - High pressure problem?

Nothing to do with expansion vessle, For pressure to increase, water has to get into system, Otherwise pressure will go up when system on, down when off. Check your fill loop valve, if not off fully, pressure will creap up. If valve ok, try disconnecting, should have a non return valve in line anyway, to stop water going from system back into mains supply, SO it should be possible to disconnect, I have however know some non returns to leak out, from the mains supply. BUT valve should stop any getting to system. Should be about 1 bar cold.

SD
January 2012