Hi, We've got a Worcester Hi-Flow 400 boiler that had a major renovation between Nov and January this year. Basically Worcester came out and replaced the expansion vessel, heat exchanger, pump... before realising there was a hole in the tank (eventually replaced). Eight call-outs in all and one of the engineers told me there was nothing else to replace, it was the equivalent of a new boiler. So far so good - and it's worked perfectly ever since. However, the last couple of days - probably because the weather's warmed up - we've noticed the radiators are on when they shouldn't be. My husband got up at two in the morning to go and switch off the other night. Is the timer faulty? Can't understand why they're getting hot when there should be no demand. Any advice gratefully received, we're reluctant to get Worcester back out again...

