Is it worth fitting thermostatic valves in addition to my room thermostat?

Yes! Thermostatic valves are the best way of getting the heating in your home just right! Used in combination with a room thermostat, they adjust your heating perfectly, and you won’t end up with some rooms being overheated.

Result! Greater comfort plus energy savings!

Your room thermostat can’t do everything!

As you probably know, your room thermostat measures the temperature of the room it’s located in. If this room isn’t as warm as you want, the thermostat will send a signal to your boiler and make it run until the required temperature is reached.

But all the other rooms where the radiator valves are open will be heated up at the same time -

• sometimes too much, in the case of rooms which are smaller and better insulated than the room you actually want to heat (the reference room), and
• sometimes for no good reason, in the case of rooms that don’t have to be kept warm all the time (like a bedroom, for example).

Adjusting thermostatic valve settings

A thermostatic valve completes the task of the room thermostat by acting on a specific radiator. It actually closes off the incoming hot water when the radiator has reached the required temperature. Don’t be surprised if you can’t see it working – everything’s happening on the inside!

Settings, however, are still fairly inexact, because thermostatic valves are graduated using numbers instead of degrees Celsius. You have to choose the number that corresponds to the level of warmth you want. It’s a matter of trial and error. Once you’ve got the result you want, leave it alone as much as possible!

Some tips on how to get the best result

• Remember that the room thermostat is the boss. It tells the boiler when to stop and start. Once the temperature you require in a specific room is reached, all the radiators will go off, whether their thermostatic valves are open or not.
• If you have a fixed room thermostat, you need to choose the size of your radiators correctly so that they will be able to heat your rooms the way you want them; in the bathroom, for example, you need to fit a radiator that’s big enough to heat the room up to 24oC while your reference room is warming up to 21oC.
• The thermostatic valves in the reference room where the room thermostat is located must always be set to “maximum heat”. In fact, if you alter the valve setting, you may be interfering with the work of the room thermostat. When you move your wireless thermostat, make sure you adjust the valves in both the new reference room and the old one.
• Avoid constantly adjusting the thermostatic valve settings; if you’re cold, opening the valve fully won’t help. In fact, until the level of warmth requested has been reached, the hot water inlet valve will be fully open, even if you can’t see it! The work of the thermostatic valve is limited to stopping the temperature from going above a certain level. It only closes the valve when the required level of comfort has been reached.

Where should thermostatic valves be located?

Doesn’t your heating equipment have thermostatic valves yet? It’s always a good idea to fit some!

We recommend you fit a thermostatic valve on every radiator. But there’s no need to fit one in a room with a fixed room thermostat.

Useful information:  in Brussels, having this work done entitles you to a bonus of €10, 20, or 30 per thermostatic valve, depending on your income. Check out the Bruxelles Environnement website to find out more.