we have been experiencing water loss through the boilers reduced pressure zone valve and although we top it up daily the following morning the pressure is down to zero.I have recently changed the discharge safety valve but this has made no difference. I have checked the entire system for leaks,pipework,radiators e.t.c and found nothing obvious, any ideas ?

martin Hyde, January 2008

I have got the same problem. I changed the PRV (Pressure relief Valve) And it has made no difference the only thing to do is take the PRV back to the suppliers and get it changed. The valve seems to have settled down to 0.9 Bar. If this does not work The boiler is going to the Council tip And I will install a proper Boiler. Bosh or some other Foreign make.

Bob, January 2008

When the boiler is running what pressure is showing on bar gauge. The gauge show show 1 - 1.25 bar when the system is cold and around 2 bar when operating. If the pressure is rising to around 3 bar when operating the pressure relief valve will lift and discharge water from the system. If this is the case then the first thing to check would be the expansion vessel which may have lost its air pressure.

D.R., January 2008