Pressure reading over 3 bar?

If it is constantly reading over 3 bar then it may either the filling loop has been left open or the plate heat exchanger has pinholed and is cross leaking water from the dhw into ch, to reduce pressure bleed a rad until the pressure is between 1 & 2 bar on gauge, if pressure only rises to 3 bar whilst boiler running the it may be the expansion vessel at fault. If after all that the fault persists then you may need to call a professional or boiler manufacturer for a repair.

Steve
March 2013

u can bleed a rad from the air point it will gradually reduce the pressure as u take the water out

kash
February 2013