I've got a problem with my radiators becoming hot when I've switched the progarmmable thermostat in the hall way off. Several upstairs radiators are very hot particularly the bathroom and onsuite. Other upstairs are also warm. Some down stairs radiators are tepid. The hot water cylinder is about a year old. I've bleed all the radiators three times to get rid of any airlocks. What could cause the raidiators to become warm whilst the progammable thermostate is switched off and how can I cure the problem?.
You motorised valve for the rads may be faulty, not shutting properly. The valves are normally near the pump. Let the system get cold, put on only the hot water then feel the pipes around the valves, if water is flowing through your heating valve when it's off, it needs repaired/replaced.