Worked fine til 2 days ago. Now the CH is fine but i have no hot water. If timer for both comes on boiler fires up, however, if i just want hot water, the boiler does NOT fire up. Why & help.

Janet Golby, March 2009

sequence of operation for hot water, programer then hot water cylinder stat, zone valve /y plan valve which closes a switch in valve which sends power to fire boiler .so you need to know if you have two zone valves or one y plan valve the fault is on one of these or the programer or cylinder stat 240volts so becarefull i would get a heating engineer

craig bg, March 2009