my vokera boiler keeps obliterating the blowout valve everytime it is pressurised, it has had a new valve but continues to blow them ,the hot water will only go to 40) and no higher then woosh the valve blows again ,a plumper has spent 4 hours trying to work out what is wrong ,any clues would be appreciated

rick, March 2006

pressure vessel as most likely gone are both valves flow and return open. is punp running.the vokera as a problem with the knobs on the front breaking in the pcb they feel like they are ok but are not.boiler will run but won get hot.go to boards and turn stats up manually.are rads open so water can circulate.

paul, March 2006