my boiler will only run on central heating and water instead of hot water only.a new pump was fitted by an engineer it was after this that i can only have hot water and heating.ive looked behind the switch and all the wires are conneced but i dont know if there wired up correctly.

dave, November 2009

sounds to me like your three port valve is seized or motor heads burned out thats why it will only do two together cos its stuck in mid position. valves the one in your cylinder cuboard RIGHT NEXT TO CYLINDER with three pipes coming off it saying A. B . A/B valve has a lever on back try moving lever with boiler programmer of etc.. youll soon know

tim the boiler man, November 2009