On Dec 17, 4:39*pm, "Gareth" wrote:
I posted a while ago about radiators heating up when the central heating is
turned off but just the hot water is turned on (conventional boiler).

I've realised that the radiators are also heating up - almost all of them -
when their thermostatic valve is switched off.

It seems too much of a coincidence that every thermostatic valve - about 8
of them - could be faulty.

Does this sound like a reverse circulation problem?

Sounds like you are without a bypass loop in your heating circuit.
Thermostatic radiator control valves do not necessarily have a
positive shut-off positon and those will lift given sufficient
pressure from the circulating pump.


If so is there a way of fixing it without causing too much disturbance to
pipe work?

Take the conrol head off the rad nearest the boiler, so it's on all
the time, and control its actual output with a towel.