Rads on despite heating controls off?

[OM]

My central heating is on a timer. Hot water is always constant and heating is timed to come on twice a day. Since switching heating back on for the winter the radiators in the upstairs of the house remain on despite the timer going off. The downstairs radiators work against the timer but upstairs don't. Anyone know why that might be?

[RAYMAN]

i just had a simular problem it is possible that the three way or two way zone valve is not fully closing the central heating water flow if it is simular to mine I had a honeywell control took the cover off and sprayed the mechanical parts with WD40 and kept opening and closing the valve with the little lever on the side now ok

[melgreen]

We've just moved to a house with an older heating system and had the same problem. Rang an engineer who said that with older systems the 2-way valve often fails to close off water completely so that when hot water is being heated it is also flowing through the radiators aswell. He seemed to think this was quite common/normal in older systems. We have ended up turning radiators off in an attempt to counteract the overheating. Maybe thermostatic radiator controls in each room would help?