Thermostatic radiator valves

Thermostatic radiator valves are often known by the initials “TRV”.

A TRV works by sensing the surrounding air temperature. It progressively closes down the flow through the radiator as the air temperature rises, thereby cooling the radiator so reducing its heat output, and regulating the room temperature.

They seem like a good idea in principle but the Great British Public seems to find them difficult to understand. Most people who have them don’t seem to recognise them as a heating control at all and keep them set to ‘maximum’. Understandably, people generally want their radiators to be HOT when the heating is on, and TRVs just don’t do this! 

A technical drawback is that TRVs need the boiler to be ON all the time, so hot water is available for the TRV to draw as and when it is needed. This rather defeats the fuel efficiency claimed for them in my opinion. 

I have to say that, like combi boilers, they have their applications but I just don’t like them for general use. Sorry. Yes I have them in my own house and they are not very effective. I tend to have them all set to ‘max’ too. QED.

The best application for TRVs is in a room which gets particularly warm. Perhaps the radiator is too big, or the room is south-facing and getting a lot of sun. The reason doesn’t matter. A TRV will generally keep it cool when the rest of the house needs heating.

Nowadays, fitting TRVs with a new boiler is mandatory under the Building Regulations, although not all installers insist.