As per title, have just moved into a new house (12 yrs old) where the water cylinder has been changed recently. It would appear that we can only get the Hot water working when the central heating is on (and when the room thermostat is set very high so that the bolier does not switch off, ie radiators continually hot)? Also on the boiler the Over heat thermostat keeps cutting in - and I have to press the button to reset. If anyone can help would be much appreciated. many tx Simon