Hi - I have a Worcester Bosch Heatslave 20/25 boiler that has been set on a timer for months and worked fine. When it is on it makes a noise that I noticed was not going off, even though the radiators did cool at the right time. I set it to off, and also noticed that the pressure was high, so drained some water out of a radiator and the pressure reduced back to normal. It was still making a noise even though it was off so now I have switched off the electricity supply to the boiler. When I turn it back on now it locks out and won're fire up, but still does make a noise as though it is on. Anyone have any ideas what might be wrong with it? I am hoping it is something simple!! Thanks.