New Radiator Guide
Thinking about upgrading your radiators?
Whether you’re replacing old ones, resizing for better heat output, or adding extra units, our simple guide will help you plan your installation.
Follow the steps below, or ask about our Professional Measuring Service.
Once you’ve chosen your radiator(s), simply get in touch and we’ll provide you with a bespoke installation estimate.
Measuring Guide
Depending on your needs, we can carry out different types of radiator installations:
Like-for-like Sizes
Swap your existing radiator for a new one of the same size and location – quick and straightforward.
Resizing
Upgrade to a larger or smaller radiator to improve efficiency or save space.
Relocation / Moving
Change the position of your radiator to suit your room layout.
Additional radiators
Add extra radiators to improve overall heating performance in your home.
Your New Radiator(s) in 4 Steps
1. Take some measurements & notes
2. Visit a trusted supplier
3. Place your radiator order
4. Expert Installation by our team
📏 Professional Measuring Service
Not sure about measuring yourself? Book our Professional Measuring Service and one of our heating experts will visit your home to take all the necessary measurements, ensuring your radiators will fit perfectly.
Click the tabs below to see more information and step-by-step guidance for each installation type.
REPLACEMENT – LIKE FOR LIKE SIZES
If you are happy with the position and heat you are getting from your existing radiator, this is the simplest and most cost-effective method of replacing your radiator.
Simply, follow the guide below to get the correct measurements for your replacement like for like radiator. All you will need is a tape measure and somewhere to record the measurements. Measurements are traditionally in millimetres in most shops, so it is best to record the distances in mm or cm.
- MEASURING THE HEIGHT
Place your tape measure on the lowest point of the radiator and measure vertically to the highest point. Record the height in mm or cm.
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- MEASURING THE WIDTH
Place the tape measure on the left side of the radiator and measure horizontally to the right side. Record the width in mm or cm. Make sure you only measure the radiator panel and not the adjoining valves and pipes.
- MEASURING THE PIPE CENTRES
Place the tape measure on the centre of left-hand pipe, and measure horizontally to the centre of the right-hand side pipe. Record the value in mm or cm.
💡 Important Top Tip:
It can sometimes be tricky to find a radiator that matches your existing width exactly. If you can’t find a perfect match, we recommend choosing the closest size down. This keeps your existing pipework running neatly in a straight line (for a cleaner finish) and helps reduce installation costs. We can always add small extension pieces to bridge any minor gaps.
Bear in mind that reducing the radiator size will also reduce its heat output, so it’s important to check that the new radiator still meets your room’s heating requirement. You can easily calculate this using a free online tool such as radcalcer.co.uk.
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- MEASURING THE WALL TO PIPE CENTRES
Place the tape measure on the wall and measure the distance to the centre of the pipe. This will only be a short distance. Record the value in mm. Make sure to measure to the wall and not to include any skirting boards.
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Important:
If you are aiming for a like-for-like replacement to prevent additional work, measurements 2,3, and 4 are vital to get right. Remember to always double-check your measurements!
Provided there is enough available wall space, you are free to increase or decrease the radiator height and this will not affect the installation cost.
You can use your measurements to search any online or store catalogue for radiators of the required size. Radiator styles and catalogues can be found at the end of this guide.
REPLACEMENT – RESIZE IN THE SAME POSITION
Changing the size of a radiator is a slightly more involved installation, as the pipework to the radiator will need to be adjusted to fit. If you want the visible pipework to remain straight, this will normally involve lifting the flooring and floorboards or opening up walls depending on the origin of the pipe.
You can choose any style of radiator, just make sure you size it correctly as mentioned below.
Sizing a New Radiator:
Whenever changing the size of a radiator, you should make sure that the new radiator will provide enough heat for the room. To work this out, you can use a simple online tool like radcalcer.co.uk. You will need to measure the length, width, and height of the room and put in a few other details about your room. A BTU and kW figure will be provided by the tool and can be matched to the new radiator to ensure the correct heat output. All radiators are presented with a BTU and kW figure by their suppliers.
RELOCATING / MOVING RADIATORS
Moving a radiator will require the movement/ extension of the existing pipework feeding it. Consequently, the floorboards or the wall will likely need to be opened up to reroute the pipework to the new location.
You can choose any style of radiator, just make sure you size it correctly as mentioned below. Radiator styles and catalogues can be found at the end of this guide.
Sizing a New Radiator:
Whenever changing a radiator, you should make sure that the new radiator will provide enough heat for the room. To work this out, you can use a simple online tool like radcalcer.co.uk. You will need to measure the length, width, and height of the room and put in a few other details about your room. A BTU and kW figure will be provided by the tool and can be matched to the new radiator to ensure the correct heat output. All radiators are presented with a BTU and kW figure by their suppliers.
💡 Top tip: The location of your radiator is important for heat output as well as aesthetic reasons. Despite the name, radiators mainly heat a room using convection. This requires a gap of at least 20cm in front of the radiator so make sure your new radiator location will not be covered by furniture.
ADDITIONAL RADIATOR
Adding a new radiator to your property involves connecting it to the existing central heating system. To do this, we’ll locate the nearest suitable flow and return pipes and extend them to the new radiator position. This may require lifting sections of flooring along the route to run the new pipework neatly and safely.
You’re free to choose any radiator style you like – remember to check the required heat output using a room heat-loss calculator. You’ll find a selection of recommended radiator styles and supplier catalogues at the end of this guide.
Don’t Forget Your Radiator Valves
When you buy a new radiator, remember that radiator valves are sold separately. Most suppliers can provide them at the same time, so it’s best to order both together to avoid delays during installation.
We recommend the Drayton TRV4 – a reliable and well-built thermostatic radiator valve. Valves are usually sold as a pair (pack), which includes:
- 1 × Thermostatic Radiator Valve (TRV) – controls the radiator temperature automatically
- 1 × Lockshield Valve – manually balances the system and controls water flow
Each radiator needs one of each valve – one on the flow side and one on the return. Always check that you’re ordering a complete valve pack before checkout.
Recommended Radiator Suppliers
| Stelrad | www.stelrad.com | An award-winning industry-leading manufacturer. They have a good all-round selection of radiators – online |
| Screwfix | www.screwfix.com | National supplier – local and online |
| Mr Central Heating | www.mrcentralheating.co.uk | National supplier – local and online |
| The Radiator Company | www.theradiatorcompany.co.uk | National supplier |
| Radiators 4U | www.radiators4u.co.uk | Online supplier |
