iff heating on goes round to 3 bar and lets out water outside over flow,also when runing hot tap only warm 40 degrees,have to have tap open slightley to get hot water,boiler only 3 yrs old,

andy, January 2009

Expansion vessel problem, may need repressurising or replacing. Drain system and re pressurise with a foot pump to about 1 bar ( installation/service instructions will confirm exact level) Could also be too big a system for expansion vessel, usually good for 7 or 8 rads if you have more may need an additional expansion vessel.

Peter, January 2009