A Radiator Thermostat is installed onto a Thermostatic Radiator Valve Body (TRV body).
The combination of both, the Thermostatic Radiator Valve (TRV), controls the room temperature by adjusting the flow of hot water through a radiator. TRVs are installed in water-based heating systems on the supply or, less commonly on the return connection of radiators. Radiator thermostats of this type with wax sensor fulfill the European Standard EN 215 when used with certified Honeywell Home TRV bodies. Honeywell Home radiator thermostats with Honeywell Home (HW) M30 x 1.5 connection are suitable for all TRV body and radiator inserts with M30 x 1.5 connection and 11.5 mm closing dimension.