The thermostatic radiator valve head is a quintessential piece of radiator technology. It is one of the many possible heating controls for modulating air temp across rooms. And due to its great value and easy function, it’s one of the most popular.

You will find or fit your TRV on the side of your radiator, and correct set-up enables you to maximise a single boiler and enjoy different heats across different rooms.

The TRV is a valve that self-regulates, meaning it adjusts the flow of water into your radiator depending on the setting.

The thermostatic valve head goes on top of the valve body. And as the room temperature changes, the valve head expands, adjusting a pin in the valve body so that it opens or closes.

Expansion as the room heats blocks the valve body to receive less hot water into the radiator.

Contraction as the room cools opens the valve body to receive more hot water into the radiator.

TRVs come in two main designs. They can be either wax or liquid models, with liquid thermostatic radiator valves being the more recent development. Their main bonus over wax thermostatic valves is providing quicker adjustment according to temperature changes.

Both wax and liquid thermostatic radiator valves offer automatic adjustment as opposed to your basic manual radiator valve.