was having problem with boiler not changing over from heating to rads, have changed diaphragm in diverter valve which was successful in its cure so thanks for the info guys, however this morning the boiler has lost its pressure and shut down. there are no visible leaks anywhere on system & after repressuring the boiler its all working fine, any ideas ??????

alan, February 2011

air in system?
monitor it for a day or two and if it looses pressure again you need to look in to it

A1, February 2011