My 80e loses pressure as soon as the central heating is run, have fitted a new pressure rlief valve. Pressure goes higher than 2 bar when heating is running, I then get a lockout and have to isolate the sensor for about 6 hours before I can reconnect it (because the lockout light stays on after I top the system up if I reconnect it). 2 different issues and I assume the latter is because the sensor needs cleaning up/replacing but it's the first problem I 'm really concerned about.

Dave, December 2004

you may havelost air in your expansion vessel causing pressure to rise in the system causing expansion relief valve to open and loosing water,causing lock out.check valve on expansion vessel,if there is water at the valve this may be the problem

stephen, January 2005