A range of three uniquely intelligent condensing combination boilers designed to cater for hot water needs from the modest to the demanding.  Uniquely intelligent because the selectable pre-heating function optimises response to hot water demand by learning from previous usage.  For the lowest possible running costs, output is automatically modulated in both hot water and space heating operation.  Moreover, an integral flow sensing switch means theres no need for a room thermostat to comply with Building Regulations on systems controlled by thermostatic radiator valves - making installation much easier and less costly.