Wanting your help or advice. I have an Ideal Excel C24 boiler. having problem getting hot water. central heating is ok. when any hot water tap is on either upstairs or downstairs -there is no hot water and the hot water light on the boiler is off. when i switch on the heating that light is on the boiler. when i switch on all the hot water taps in my house the light is on the boiler and i have hot water. Any advice??? Thanks