Replacing radiators is one of the best ways to reduce your energy bills as well as improving the comfort of your home.
The fact that there are now more radiators to choose from than ever before can be both a blessing and a curse. There are so many types and styles to choose it can be hard to know which is the best choice for your home. To help you find the ideal radiators, we’ve put together this guide which looks at everything from radiators sizes to their finished design.
How to Work Out Radiator Sizes
The most important thing to consider when purchasing a new radiator is the size as this will determine how well it heats up the room. So what do you need to avoid?
- Radiators that aren’t powerful enough as they won’t heat the room well
- Radiators that are too big causing the room to overheat and your energy bills to be higher than necessary
To ensure that you find the right size of radiator you will need to look at the number of BTUs it has, which is used to measure the radiators size (or power). If you’ve started browsing radiators then you’ve probably already come across this acronym, but what exactly is a BTU?
BTUs
A British Thermal Unit (BTU) shows how much heat a radiator will emit into the space around it. Simply put, the higher the BTU number is, the quicker the radiator will heat the space. A BTU represents how much energy it takes to heat a pint of water by 1° Fahrenheit. You’ll find that the majority of central heating radiators tend to have a BTU output between 600 – 10,000 or higher.
When it comes to finding the best radiator for your home, you’ll need to think about the following:
How big is the room?
Knowing the size of the room that the radiator needs to heat is vital. Make sure you have this information in square metres.
How many windows does the room have?
Every window in a room has the potential to cause a draught which is why you’ll need to think about how many there are.
How many radiators will be needed?
Larger rooms could well benefit more from having 2 or 3 smaller radiators rather than just one large radiator.
What’s above, below or on the other side of the wall?
Radiators won’t need to work as hard if they’re fitted on a solid floor, against a solid wall or under a well insulated ceiling. Watch out for radiators being fitted above cellars or against cavity walls.
By using all of this information, you can work out the size of radiator needed to heat your home. To give you a further helping hand, we’ve put together some estimates based on the average room size in the UK*.
| Room type | Size (m²) | Average Radiator Size (BTUs) |
| Living room | 17.0 | 5700 – 6825 |
| Kitchen | 13.4 | 3575 – 4300 |
| Master Bedroom | 13.4 | 3550 – 4275 |
| Bathroom | 3.7 | 1225 – 1475 |
*Research conducted by LABC Warranty using open data from property sites Rightmove and Zoopla. The study looked at 10,000 houses built in the 1930s, 1940s, 1950s, 1960s, 1970s, 1980s, 1990s, 2000s and the current decade. All statistics are calculated on average. Calculations based on a standard ceiling height of 2.4m² with double glazed windows.
How Much Does Replacing a Radiator Cost?
There are 3 different types of job when it comes to replacing a radiator, with an average cost of around £100 – £300:
- Like for like replacement: £100 – £200
- Relocation of an existing radiator: £100 – £150
- Installation of an additional radiator: £150 – £300
The above are estimates and the labour costs will vary depending on your location, the complexity of the work and the engineer you hire to carry out the work.
What will the quote include?
- Price of the radiator
- Any additional pipework
- TRVs (Thermostatic Radiator Valves)
- Labour (draining and removing the old radiator, opening valves, adding new pipework, mounting, filling and bleeding the new radiator etc.)
To give you the greatest chance of getting the best price for your radiators, you should compare quotes from several companies. It’s worth getting quotes from some smaller independent engineers because if the business’ turnover is less than the VAT threshold they aren’t legally required to charge VAT, which means that they’ll be able to offer cheaper prices.
Will I Need a New Boiler When Installing an Additional Radiator?
Adding radiators to your home will mean that there’s extra demand for heating, which will have an impact on your boiler. If you’re only looking to add 1 or 2 radiators then you should be fine but installing any more than that then you’ll need to get a professional engineer to assess your heating system.
Which Type of Radiator Should I Install?
When it comes to how a radiator is powered, they can either be plumbed to the central heating system or electrically powered.
Plumbed radiators are connected to your hot water system via pipework. In many homes, a boiler will heat water from the mains which then travels around the pipes and radiators. You’ll need a plumber or heating engineer to install these radiators. Electric radiators are controlled individually, only requiring a mains electricity supply in order to work.
This takes into account how they work but in terms of how they’ll look on the wall, there are a few different types of radiator available. Use the table below to find out what each one offers:
| Type of Radiator | How it works |
| Steel Panel Radiators | The cheapest and most energy efficient option. You can spot a steel panel radiator by their corrugated or wavy panels which help to increase their surface area thus emit more heat.
If the white colour of steel panel radiators puts you off then you can always house it in a radiator cover or cabinet to keep it safely and discreetly out of sight. |
| Column Radiators | Made of vertical pipes, column radiators are more suited to traditional or period homes but while they may look Victorian, they deliver modern heating efficiency.
They come in a range of sizes and with either 2, 3 or 4 columns – the more columns the radiator has the more heat it will emit. To keep them running efficiently, they will need to be brushed regularly as dust can get trapped between the columns. |
| Designer Radiators | These radiators are rapidly increasing in popularity as they can help save space and be fitted into the decor of the home.
As they’ve risen in popularity, some are now intended to be the main focal feature of a room. Some can double up as heated towel rails, mirrors and magnetic memo boards. They’re also available in a variety of colours and finishes such as black, chrome, stainless steel or even wood veneer. |
What are Thermostatic Radiator Valves?
Thermostatic radiator valves (TRVs) are required for every plumbed radiator installed around your home and allow you to control how much heat a radiator emits. To do this, they monitor the temperature of the room, after reaching the required temperature the TRV turns the radiator off. One benefit of TRVs is that you can have different rooms set to different temperatures, so you’re not wasting energy by heating rooms that are empty.
The best thing about TRVs is that they don’t have too much of a price tag attached to them, available from as little as £5. Smart TRVs are also an option and they allow you to control the temperature via an app on your smart device and cost around £30.
Where Should a Radiator be Installed?
It’s important to have a good think about where your new radiators are going to be installed as this could have an impact on the size and type of radiator needed.
Walls and brickwork
When it comes to brickwork, blockwork or solid masonry walls, they’ll accommodate most types of radiators as long as they’re attached using the correct fixings. In most cases, there won’t be any restrictions on where you can hang the radiator.
Fitting a radiator to the wall gets a little more difficult when it comes to studwork or drywall that have a hollow space behind them. There are studs, which are vertical and horizontal pieces of timber which the plasterboard attaches to, where the radiator has to be attached. This could then put restrictions on the size and type of radiator you can install.
It’s not a good idea to mount a new radiator onto walls that are crumbling or have any cracks so make sure you address anything like that before going ahead with the installation. So if you’re planning to redecorate, get your paintbrush out before putting the radiator up.
Existing Plumbing
The pipework in the room will also need to be considered. Pipework which runs along the wall is the simplest scenario as you should be able to fit a radiator of the same width or wider with minimal pipework cutting. Should the new radiator be smaller than the pipework then a bit of extra pipework may be needed to bridge the gap.
Pipework running up from the floor can be more complex if the size or style of radiator is being changed as floorboards may need to be lifted during installation.
Is there an Alternative to Radiators?
If wall-hung radiators aren’t possible in your home or you’d like to explore alternative central heating methods then it’s worth looking into underfloor heating or skirting board heating.
Do Radiators Require any Maintenance?
To ensure that your heating system is running as efficiently as possible, radiators will sometimes require maintenance. Some of which can be performed yourself but if in any doubt, contact a professional.
| Type of Maintenance | What’s Involved? | Is a Heating Engineer Required? |
| Bleeding Radiators | To keep radiators working effectively and keep your energy costs as low as possible, it’s important to bleed radiators on a yearly basis. This is necessary because air bubbles can build up preventing hot water from filling the radiator. Less surface area for the heat to emit from the radiator means that you may need to leave the boiler running for longer to get the room at the temperature you desire and that means higher fuel bills. Bleeding the radiators will allow the air to escape. | This can be performed yourself or by a heating engineer and will cost around £75 – £150. |
| Balancing Radiators | In the case that some of your radiators are taking a long time to heat up you may need to adjust a ‘lockshield valve’. | Balancing radiators can be done by yourself or an engineer after the radiators have been bled. |
| Flushing Radiators | Over time, heating systems can fill with debris, rust or sludge that needs to be flushed out using chemicals. To help prevent this happening or reduce the build up, a magnetic filter can be installed.
Every now and then, flushing radiators can find leaks in the system and reveal the need for a new radiator, helping to ensure your heating is running efficiently. This is often called a Powerflush and can cost around £300 – £600. |
Must only be performed by a professional. |
