Got a relatively new vokera boiler - 18 months old and it has developed a problem over winter. Fault warning - flashing green LED 120hz comes on - manual says temporary fault. Then eventual RED comes on and the unit stops heating. I notice at ignition time the pressure is in the correct range 1-1.5 bar but it increases over 1.5 and shortly after the unit fails. Why is water pressuer increasing? Ive checked the crossfeed and its not leaking

Mark Gordon, April 2009

check pressure in expansion vessel if that ok, its possible but rare for plate to plate heat exchangers to pass from d/h/w to c/h

STE, April 2009

Sorry should have said 2Hz that is 2 flashes per second

Mark Gordon, April 2009