Strathclyde Switch OffHeating Control Guidance

Thermostatic Radiator Valve

Thermostatic radiator valves

Thermostatic radiator valves (TRV) are a type of control found on most radiators.  

They work by sensing the temperature around the radiator and will open or close the flow of hot water to the radiator to reach the temperature setting.  

Most valves are labelled 1-5. This roughly corresponds to the following approximate temperature settings:

  • 0 = Off 
  • * = 5-7°C 
  • 1 = 8-12°C 
  • 2 = 13-17°C 
  • 3 = 18-21°C 
  • 4 = 22-25°C 
  • 5 = 26-30°C 
Did you know?

Turning the valve to 5 will not make the room heat up any faster - rather, it will keep heating the room beyond a comfortable temperature. Try setting it to 3 and allow the TRV to regulate the temperature automatically. 


Thermostats come in many shapes and sizes. The most basic will allow you to set a temperature for the heating to come on at. The Energy Saving Trust recommends a set point of 18-21 degrees to maintain comfort levels. 

Most thermostats will allow you to set up programmes, setting temperature and times of day for the heating to come on and turn back off. Your thermostat instructions will contain guidance for this. If you are away from home or the office is not occupied for long periods of the day, try setting up schedules to turn the heating off when it isn’t needed.  

You could also turn down or switch off radiators in rooms that aren’t used, to reduce heating demand. Just remember to keep a frost protection setting (where the heating will come on if temperatures drop below freezing) to ensure pipes and plumbing is protected if you are away for longer periods.