I have ravenheat RSF100ET which serves 11 rads over 3 floors with no problems. However during a heating cycle teh pressure on the gauge will increase from the 1 Bar red mark to around 2.5 bar. After it goes cold, you notice it drops below 1 Bar. It keeps getting rid of water through the over flow although the pressure doesn't go above 2.5 bar. Any ideas please?

Bipin, December 2010

It sounds like the diverter valve is faulty

raven, June 2011