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 liquid sensor fulfill the European Standard EN 215 when used with certified Honeywell Home TRV bodies.
