The problem with this multi point hot water heater is the pilot light does not stay on for long. As soon as you turn the hot tap, the water would heat up for about 2 to 3 minutes and then the heater would cut out (including the pilot light). And if you try to relight it, the pilot would not stay on. It takes another 2 to 3 minutes of trying before the pilot stays on. (it looks as though the boiler has to be cool before the pilot stays on, and as soon as the boiler heats up, it cuts out again). I have replaced the thermocouple and it is still the same. Any ideas, please help. Boiler make is MAIN, Model = Mersey Super