My combi boiler has developed a strange problem in that no matter what setting my time clock or thermostat is on my radiators remain hot. The boiler says it is still on standby, but the only way to get them back cold again is by turning the boiler off totally. Firstly am I going to damage the boiler by switching it on and off frequently, secondly does anyone have any ideas about what the fault could possibly be? Thanks in advance!