I have a Halstead ACE boiler. :?
After long draw offs of hot water the boiler will lock out due to overheating. I have recently changed the secondary heat exchange to resolve another issue but can't be sure why the boiler is now overheating.
I suspect that after a run of hot water, the boiler is supposed to divert the remaining hot water into the central heating system so that it doesn't remain in the boiler but this doesn't happen.
Can any one tell me if my suspicion is correct? What controls it?
Or what the problem is if I'm way off base?