A thermostatic radiator valve detects room temperature and will control the heat level of the radiator to keep the temperature at a constant setting. Most have an off setting, a frost setting (for rarely used rooms) and then numbered calibrations. These valves can save you money and reduce your home’s carbon emissions from day one.
8 You should not fit a radiator thermostat in the same room as the room thermostat that controls the overall boiler output. If you have any doubts, consult your supplier or a professional before starting work.
Fit The New Adaptor - Fit the new adaptor, cap nut and olive (the metal collar) onto the radiator. Clean the internal threads with a clean cloth and wrap some PTFE tape half a dozen times around the adaptor threads, winding it clockwise. Screw the adaptor into the radiator and tighten.
Refill The Heating System - Refill the central heating system and check for leaks. Set your living room valve to fully open and your bedrooms to a lower setting. You don't need to constantly change the settings as you use the rooms. If you have a spare bedroom, put the valve on the frost or minimum setting and keep the door closed so that the adjacent radiators don't try and compensate for the drop in air temperature.