People are only just realising what the numbers on radiator knobs mean – but my tips can HALVE your gas bill

PEOPLE are only just realising what the numbers on radiator knobs mean, and they could actually halve your gas bill.

These handy add-ons at the end of your radiator are known as thermostatic radiator valves (TRVs) and they can save you energy this winter.

That's because if you've got a TRV attached, you'll be able to limit or turn off the flow of hot water into the radiator.

This can help reduce the amount of gas that your boiler needs to burn to heat up the water in your central heating system.

They tend to use less gas which will reduce your bills when you have your central heating on.

The Sun spoke to Nicholas Auckland, a heating expert from Trade Radiators to find out exactly what those numbers on our TRVs really mean.

He said: "Thermostatic Radiator Valves allow you to have complete control over the temperature of individual radiators, and by installing TRVs, you can save money on your heating bills. 

"However, it's important to note that the numbers on the thermostatic valve do not indicate the radiator temperature."

Nicholas went on to say that the numbers on a thermostatic radiator valve actually refer to the temperature in the room, not the radiator itself.

He added: "This is a really common misconception, and the majority of people automatically assume that the numbers relate to the radiator instead.

"The main point of a thermostatic radiator valve is that it can easily detect the temperature in the room, therefore letting more or less hot water into the radiator as needed."

Essentially, if the room is cold, the TRV allows more hot water into the radiator in order to heat it up.

As your room gets warmer, the TRV then restricts the amount of hot water coming into the radiator in order to maintain the temperature.

If the room temperature starts to drop, the TRV will let more hot water in.

The numbers or symbols on the valve roughly indicate the corresponding room temperatures, Nicholas explained.

When the room temperature falls below these values, the TRV will open to let hot water flow into the radiator.

Here's how the numbers correspond with the temperature:

• 0 = Off
• * = 7°C
• 1 = 10°C
• 2 = 15°C
• 3 = 20°C
• 4 = 25°C
• 5 = 30°C

Nicholas said: "A functional TRV will quickly detect the temperature of the room, and then automatically adjust the amount of hot water in the radiator accordingly."

How to work your TRV during winter

Nicholas also shared his tips on how to use a TRV during the colder months.

He explained: "During the winter, I recommend that you set your TRV to 2 or 3 and leave it at that.

"If you enter a cold room and the radiator is excessively hot, you should really refrain from increasing the TRV setting to 5.

"Let the TRV function on its own to heat the room as needed."

Another key trick is that if you're away for a longer period during winter, set your TRVs to the * icon.

That means the radiators will turn on for a brief period if the temperature drops below 7°C.

How to use your TRV to save money and energy

If you set your TRV to 5, it means that it will continue to let hot water into the radiator until the room temperature reaches around 30°C, Nicholas said.

He added: "This is not necessary as you hardly ever need the room to be that hot, and it also means you won't be able to save on heating bills because the hot water will be constantly running.

"The most effective method when using thermostatic radiator valves is to decide on a desired room temperature and adjust the number on the TRV accordingly to that."

He also added that it's important to not frequently adjust TRV settings.

This is because it diminishes their money-saving features.

Meanwhile, a boiler engineer has revealed the forgotten setting adding £108 a year to energy bills and how to change it.

Plus, these are the three sounds you mustn’t ignore on your radiator but another isn’t anything to worry about.

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