I have been having problems for months with this. I have had several engineers look at it all diagnosing different problems. I have had a full power flush. The problem is it will work for a while and then trip out about every 15 minutes. I noticed it was worse when the central heating was off. Now it is doing it when the heating is on.

karen brown, November 2010

have to assume system is clean has not airlocked and pump okay and main boilerstat okay (switching off before 85oC...
95oC overheat stat is proned to be weakened by multi-trips.
replace it

deano, November 2010