The numbers on a thermostatic radiator valve refer to the temperature in the room, not the radiator. The numbers on the valve roughly correlate to the room temperatures below:
- 0 = Off
-
- = 7°C
- 1 = 10°C
- 2 = 15°C (Typically Ideal Setting range)
- 3 = 20°C
- 4 = 25°C
- 5 = 30°C
During the winter, you should set your TRV to 2 or 3 and leave it. If you go into a room thats cold and the radiator is burning hot, leave it alone and dont turn it up to 5. Let it do its job and allow the TRV to heat the room accordingly. Ultimately, the lower the number your thermostatic radiator valve is set at, the less water flows around the radiator and the less heat it gives out. Setting your radiator value to max (usually 5), means you’re requesting more water flow than the other settings.
