Sorry for the lack of detail :oops:
Boiler is Glowworm Ultimate, system is open-vented fully-pumped,
Y plan (I think).
5 rads downstairs, 4 upstairs. Everything installed in 1997.
HW Cylinder, Pump etc in upstairs cupboard. Boiler is in kitchen.
James
Last week my central heating went off when it was set to be on, I
managed to restart it by powering off/on the controller/boiler.
Since last night the central heating only works when the hot water
program is active. As soon as the HW program goes off then the
central heating doesn't work...