Thermostatic Radiator Valves?

They are very effective. Few people want a bedroom (for example) as hot as their living room. Note that if you turn the radiator 'stat down in any single room then you should keep the door shut so that the remaining household radiators don't try and heat the cool air in that room. This is an important point that many people don't appreciate. If you have a room thermostat and a radiator thermostat in the same area then they will work against each other. The radiator 'stat will try and shut the radiator down because of the warm air in th room; the wall stat will try and crank up the boiler because of the cool radiator. You'll end up burning loads of gas and having a cold room. Actually, it's normally the house's hallway. So, when you fit thermostatic radiator valves (good idea) do not fit one to the radiator in the same room (or hall) as your wall thermostat.  more