How to use radiator valves to lower the heating bill

The flat has been feeling pretty cold these days and as we’re working from home, I am definitely feeling it more! As much as I would like to have the heating on all day, it wouldn’t be good for our finances so we have set the room thermostat to switch on the heating at certain times of the day but we didn’t know what to do with the radiator valves!

Have you ever wondered what the numbers on the radiator valves mean?

I did a few weeks back and realised that I had no idea! I wasn’t even sure what a radiator valve actually does!  After doing some research online, I found some useful guides and articles so wanted to share with others.

What is a thermostatic radiator valve (TRV) used for?

It turns out the valve controls the flow of hot water to the radiator, which in turn controls the air temperature in a room. You set it at a certain level (the numbers you see on the valve, but we’ll get to that later on) so that it will regulate the flow of hot water to give your desired room temperature. TRVs don’t control the boiler. They are also different to a room thermostat. A room thermostat sets the temperature for the overall home.  

TRVs give you greater control which helps to make the heating more cost-effective, as you can have different temperatures in rooms. For example, you can set a lower temperature in the hallway than the living room, which saves energy and in turn can lower your heating bill.

How do TRVs actually work?

There is a sensor inside which contains a material which will expand when room temperature goes up and contracts when the room temperature goes down. This movement in the sensor in turn causes a valve to open and close. 

If the temperature in the room is too low, the sensor will contract and allow more hot water to flow into the radiator and so this will increase the room temperature. We mentioned earlier that the user sets the TRV to a certain level and so when the room reaches that temperature, the sensor will have expanded which in turn will close the valve, restricting the hot water flowing into the radiator so it won't keep getting hotter.

If you want a more detailed explanation, this guide from the Heating and Hot Water Industry Council was really helpful!  This post from BoilerGuide.co.uk was also helpful!

I also thought the infographic from BestHeating.com on the different room temperatures in the home was useful too.

Tip:

Don’t cover the TRV with curtains or block it with furniture as it needs a free flow of air to sense the temperature.

So now we know what the valve is for and how it works, what do the numbers mean?

It turns out the numbers do not represent specific room temperatures!  The valves don’t have a specific temperature because the room temperature is impacted by a number of factors, from room size to heat loss from windows. The numbers on the valve is to show the settings which provides more heat (higher number) or less heat (lower number).

How do you set it?

The guide from the Heating and Hot Water Industry Council has a section on how to set the room temperature.  It advises using a room thermometer to measure the room temperature and then set the number on the valve.

If like me, you don’t have a room thermometer to hand, not to worry!

The Energy Saving Trust has a short video on how to use your thermostat efficiently.  In the rooms that are used, they recommend setting the TRV at 3 or 4 to start with but to use a lower setting in bedrooms and rooms that you use less and then adjust accordingly until you have your preferred temperature.

From reading this guide on the Energy Saving Trust, a lower setting on the TRV uses less energy.

There are also more tips on setting the TRV in this BestHeating.com post, in the ‘My TRV isn’t working properly’ section.

Tip:

Turning a radiator thermostat up will not heat the room up quicker but will cost you more money!

Did you know?

For this type of heating system, there’s always at least one radiator without a TRV. We had spotted this in our flat and initially thought we had a valve missing!

Hope this post was useful!  You might also be interested in my other blog post on 10 tips to reduce the heating bill. Subscribe to get the latest posts sent directly to your emails and follow on Instagram for more tips and home decor ideas! 

Jess