As temperatures drop, you will find yourself using your heating more often.

Turning on your radiators during winter is, of course, one of the first and most essential steps to warming up your home.

However, many of us tend to crank up our radiator valves without fully understanding what those small numbers actually indicate.

Thermostatic radiator valves (TRVs), typically numbered from one to five, are often misunderstood. Contrary to popular belief, these numbers don’t indicate the radiator’s temperature. 

Instead, British Gas engineers explained that TRVs sense the room’s temperature and adjust the radiator to maintain your desired warmth.

Each number on the TRV corresponds to a specific temperature range. 

For instance, you might set your cozy living room to three or four, keep an unused spare room at one, or set an already warm kitchen to two. This allows for tailored heating throughout your home.

The engineers at British Gas said: “All you need to do is turn the dial on the TRV in each room so it is only as warm as you want it. 

“This greater control over your heating can help reduce the amount of energy you use, which can in turn save money.” 

A TRV consists of two main components: the head and the body. It regulates the flow of hot water to your radiators, ensuring they stop heating once the room reaches the desired temperature.

As the room's temperature changes, the TRV head expands, pushing a pin into the valve body. If the room becomes too warm, the valve closes, cutting off the flow of hot water to the radiator. 

Conversely, if the room is too cold, the valve opens to allow more hot water in, maintaining the set temperature.

If your heating system includes a room thermostat, a TRV may not be necessary.

The key benefit of TRVs is their ability to help you avoid heating areas of your home that are not in use, which means "you'll be reducing your energy usage and saving money", says the expert.