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Replacing a radiator - a complete guide
The radiators in our homes are incredibly important, keeping us warm and comfortable, especially during the coldest months of the year. While radiators generally have a long lifespan, years of constant use can cause them to become less efficient, leading to higher energy bills and uneven heating. Eventually, the time comes when replacing them is the best option.
Much of the UK's housing stock still has radiators that are decades old, meaning many homeowners may have inefficient heating systems without even realising it. Over time, the continuous flow of water through radiators and pipework causes internal rust, which settles at the bottom of the radiator as a thick, sludgy residue. This sludge reduces the radiator’s ability to heat up properly, making your boiler work harder than necessary—leading to increased gas bills and wasted energy.
One of the clearest signs of an ageing, sludge-filled radiator is when it feels hot at the top but remains cool or cold at the bottom. If this sounds familiar, it may be time to consider upgrading your radiators to a newer, more efficient model.
In this guide, we’ll take you through everything you need to know about replacing a radiator, from choosing the right one to installation considerations. Whether you’re looking to improve efficiency, update your home’s style, or simply ensure your heating system is working at its best, we’ve got you covered.
Why replace your current radiators?
Radiator design and efficiency have improved massively in recent years, and upgrading your heating system can bring both practical and aesthetic benefits. While radiators are built to last, older models can become inefficient over time, leading to poor heat output and increased energy costs. Below are some key reasons why replacing your radiators could be a smart investment.
1. Your radiators aren’t heating efficiently
Older radiators often struggle to distribute heat evenly, leaving rooms feeling colder than they should be. A common sign of an inefficient radiator is when it feels hot at the top but remains cool or cold at the bottom. This is usually caused by a build-up of sludge, which are tiny flakes of rust and debris that accumulate over time.
This sludge creates a barrier between the hot water and the metal surface of the radiator, making it much harder for the heat to transfer into your room. As a result, your boiler has to work harder to compensate, leading to increased energy consumption and higher heating bills. If you find yourself constantly turning up the thermostat but still not feeling the warmth, it could be a sign that your radiators need replacing.
If sludge build-up is the main problem, you may be able to restore performance by flushing the radiator instead of replacing it. A power flush or a chemical flush can help remove the sludge and get your heating system running efficiently again.
- Further reading: How to Flush Sludge Out of Your Radiator.
2. Your radiators are outdated & inefficient
Older radiators were designed with older heating technology, meaning they often don’t provide the same level of efficiency as modern models. Today’s radiators are designed to heat up faster, distribute heat more evenly, and retain warmth for longer, meaning you can enjoy a more comfortable home while using less energy.
Newer radiators are often designed with high-performance materials such as aluminium, which conducts heat far more efficiently than traditional steel models. Aluminium radiators warm up quickly and require less water to operate, making them a great energy-efficient choice.
Additionally, many older radiators were made with single-panel designs, whereas modern options feature double or triple panels with convector fins, which significantly increase heat output without taking up much extra space. If you’re struggling with slow-heating radiators or find that certain rooms never quite reach the right temperature, an upgrade could make a big difference.
Further reading: Why it's Time to Upgrade Your Radiators if They're Over 15 Years Old
3. Your radiators look old & worn
Radiators don’t just provide warmth—they also contribute to the overall look of your home. If your radiators are scratched, discoloured, rusting, or simply outdated, they may be dragging down the appearance of your space.
Modern radiators come in a wide variety of styles, including sleek, minimalist designs, vertical radiators for space-saving solutions, and designer models that can add a stylish touch to any room. Whether you prefer a contemporary aesthetic or a more traditional look, upgrading your radiators allows you to enhance your home’s décor while improving heating performance.
However, if your radiator is still functioning well but just looks a little worse for wear, you could consider painting it instead of replacing it. Special heat-resistant radiator paint can give your radiators a fresh new look without affecting their efficiency.
- Further reading: The Complete Guide to Painting a Radiator.
4. Your radiators are hard to keep clean
Over time, radiators collect dust, dirt, and grime, which can reduce their efficiency and make them look unsightly. This is particularly true for convector radiators, which have small fins that easily trap dust.
If you have pets, children, or a high-traffic home, your radiators may get dirty more quickly. Regular cleaning can help maintain their efficiency, but if your radiators are difficult to clean due to their design or years of grime build-up, replacing them with a more modern, easy-to-maintain model may be a better option.
- Further reading: The Complete Guide to Cleaning a Radiator.
5. Repairing your radiator may not be enough
Sometimes, a minor repair or adjustment can restore an underperforming radiator. For example:
- Leaky valves – A PTFE tape wrap around a valve’s thread can stop small leaks.
- Pinhole leaks – If your radiator is leaking water due to corrosion, you may be able to apply a temporary sealant, but the damage will only worsen over time.
- Trapped air – If a radiator has cold spots at the top, it may just need bleeding to remove trapped air.
- Unbalanced heating – If some radiators in your home are heating up more slowly than others, they may need balancing to ensure hot water is distributed evenly.
However, if your radiator has multiple issues or leaks that keep reappearing, a full replacement will likely be a more cost-effective and long-term solution.
How much does it cost to change or replace a radiator?
The main cost factor when replacing a radiator is whether you hire a professional or do it yourself.
Hiring a professional
If you're not confident in DIY plumbing, hiring a qualified plumber or heating engineer is the safest choice. A professional ensures the job is done correctly, preventing leaks, incorrect pipework adjustments, or damage to your heating system.
If multiple radiators need replacing, it’s often worth bringing in a professional. In older homes, pipework may need rerouting to optimise space, a job best handled by an experienced tradesperson. Additionally, if radiators haven’t been replaced in years, your gas boiler may also be outdated. A Gas Safe Registered Engineer can assess its condition, ensuring it runs safely and efficiently, and recommend any necessary repairs.
Several factors influence the final cost, including the number of radiators, home size, and whether pipework needs adjusting. Location also plays a role - labour costs in London, for example, are typically higher than in Carlisle.
(For electric radiators, a qualified electrician must install them to comply with legal safety regulations, this is not a DIY job.)
Below are cost estimates from Checkatrade, providing 'ballpark averages' per radiator:
| Remove a small radiator | 1 hour | £80 |
| Remove and repair radiator | 1-2 hours | £125 |
| Remove and replace a double panel radiator | 1-2 hours | £200 |
| Replace a large radiator | 2 hours | £300 |
| Move a radiator | 2 hours | £275 |
Please note that the above describes the labour costs for a professional to replace a radiator, it does not cover the cost of the radiator itself.
Most professional tradespeople will be able to advise the best type of radiator for the room and will perhaps give you ideas you hadn't previously thought of. If you don't have any particular preference in terms of design and just want something that heats the room efficiently, then leaving it up to the tradesperson could be a great, low-stress choice.
- Further reading: What is the Cost of a New Radiator?
But if you do have something special in mind then you may find it preferable to order your chosen radiator yourself and simply get the professional to install it. Many tradespeople have a favoured brand or style of radiator that they like to install and these may not necessarily be to your taste. Choosing your radiators yourself means you'll get exactly what you want and for a price you have control over before getting the labour costs from the professional.
Make sure you use our Heating Calculator to input your room's dimensions so that you know what size and heat output you need from your radiator to comfortably heat the room.
Doing it yourself
If you have some basic plumbing knowledge, you may be able to replace the radiator yourself, particularly if it’s a like-for-like replacement (i.e., the same size and type, with no need to move pipework). If you feel confident in your DIY skills, replacing a radiator yourself could save £100-£300 in labour costs. However, if pipework needs altering, it's best to call a professional in order to avoid accidents that could potentially cause nsty water damage to your property.
- Further reading: How to remove a radiator
Replacing a radiator - step by step guide
Tools you'll need
- Adjustable spanner
- Radiator key
- Bucket & towels
- PTFE tape
- Pipe wrench
- Spirit level
- New radiator & brackets
- Bleed valve & TRVs (if replacing)
Instructions
- Turn off the heating - Ensure your central heating is off and the system has cooled down completely.
- Isolate the radiator - Close the thermostatic radiator valve (TRV) and the lockshield valve on either side of the radiator.
- Drain the radiator - Place a bucket under one valve. Loosen the nut connecting the radiator to the valve, allowing water to drain. Open the bleed valve with a radiator key to speed up drainage.
- Remove the old radiator - Once drained, fully undo both valve connections and carefully lift the radiator off its wall brackets. Tip it slightly to drain any remaining water into the bucket.
- Prepare the new radiator - Wrap PTFE tape around the valve threads for a better seal. If new brackets are needed, mark and drill holes to secure them, ensuring the radiator sits level.
- Install the new radiator - Hang the radiator on its brackets and reconnect it to the existing valves. Hand-tighten the nuts before securing them with a spanner.
- Refill & bleed the radiator - Open the TRV and lockshield valve, allowing water to flow back in. Bleed the radiator to remove trapped air.
- Check for leaks & test - Turn the heating back on and inspect for leaks. Ensure the radiator heats up evenly.
By following these steps carefully, you can successfully replace your radiator without professional help.
For an even more in-depth guide, take a look at this video tutorial from a professional plumber talking you through the process of replacing a radiator step by step.
Frequently asked questions (FAQs)
Cost and Budget
﹢ How much does it cost to replace a radiator?
The cost varies depending on the radiator type, size, and whether you hire a professional or do it yourself. Hiring a plumber typically costs £100–£300 per radiator, including labour, but this can be higher in London. If DIY, you only pay for the radiator and any additional materials. See our table of labour costs from Checkatrade earlier in this article.
You can find out more at What is the Cost of a New Radiator?
﹢ How much does a new radiator cost?
Prices vary based on size, material, and brand. A basic panel radiator starts at around £50–£100, while designer radiators or cast iron models can cost £300+. Larger, high-output radiators will be more expensive.
See our full range of radiators at Trade Radiators - Full Radiator Catalogue
﹢ Is it cheaper to repair or replace a radiator?
For older, inefficient radiators, replacement is usually the better long-term investment. Repairs (e.g., fixing leaks or removing sludge) may offer a temporary fix, but an old radiator will still struggle to heat efficiently, leading to higher energy bills.
﹢ How can I save money on radiator replacement?
Opt for DIY installation if you’re confident in basic plumbing. Choosing a standard size avoids pipework alterations, and shopping around for deals from online retailers can cut costs. Compare local tradespeople for the best installation price.
For more information, view How To Remove A Radiator
You might also like to view How To Install A Column Radiator
﹢ Do I need to drain the whole heating system to replace a radiator?
No, you can isolate the radiator by closing the valves before removal. However, if replacing multiple radiators or adjusting pipework, a full system drain may be required.
You can read more at How To Isolate A Radiator - A Complete Guide
DIY vs Professional
﹢ Can I replace a radiator myself?
Yes, if you’re comfortable with basic plumbing. Swapping a like-for-like radiator is straightforward, but resizing or repositioning requires pipe adjustments, which can be trickier.
For more information, view How To Install A Column Radiator
﹢ Do I need a plumber to replace a radiator?
If you’re unsure or need pipework modifications, hiring a professional is safest. A plumber ensures correct installation, preventing leaks or heating system damage.
For more information, view Who Should You Call To Fix A Radiator
﹢ How much do plumbers charge to replace a radiator?
Costs vary by location and job complexity. Expect to pay £100–£300 per radiator, with higher rates in London. If pipework needs adjusting, costs may rise. See our costs table earlier in this article.
Remove a small radiator 1 hour £80 Remove and repair radiator 1-2 hours £125 Remove and replace a double panel radiator 1-2 hours £200 Replace a large radiator 2 hours £300 Move a radiator 2 hours £275
Choosing a New Radiator
﹢ What type of radiator is best?
It depends on your needs and budget. Panel radiators are cost-effective, column radiators add a classic look, designer radiators make a statement, and towel rails suit bathrooms.
For more information, view The Best Radiators By Style
﹢ What size radiator do I need?
Use a BTU (British Thermal Unit) calculator to determine the right size based on your room’s dimensions and insulation. Trade Radiators’ heating calculator can help.
﹢ What's the difference between single, double, and triple panel radiators?
Single panel radiators are slim but provide less heat. Double panel models have an extra layer for improved warmth. Triple panels offer the highest heat output but take up more space.
You can read more at What's The Difference Between Single & Double Panel Radiators?
﹢ What are the most efficient radiators?
Efficiency depends on material, surface area, and water flow. Aluminium radiators heat up quickly and retain heat well, while double-panel models distribute warmth efficiently.
You can read more at Which Type of Radiator is the Most Efficient?
﹢ Where can I buy a new radiator?
At Trade Radiators, we provide top-quality radiators at unbeatable prices, all with warranties of up to 25 years for long-term peace of mind. Our extensive range features stylish and efficient models from leading brands, ensuring you’ll find the perfect fit for your home. Plus, we offer free next-day delivery on select UK orders. If you need advice on choosing the right radiator, our knowledgeable team is ready to assist.
Get in touch with us today, we’re always happy to help!
Installation & Technical Issues
﹢ How do I bleed a radiator?
Turn off the heating, use a radiator key to slowly open the bleed valve at the top, and let out trapped air until water dribbles out. Close the valve and check pressure levels.
You can read more at How To Bleed A Radiator - A Complete Guide
﹢ How do I balance my radiators?
Adjust each radiator’s lockshield valve to ensure even heat distribution across all rooms. This prevents some radiators from overheating while others stay cold.
You can read more at How To Balance A Radiator - A Complete Guide
﹢ What are TRVs?
Thermostatic Radiator Valves (TRVs) regulate temperature automatically, improving efficiency by only heating rooms when needed. They’re ideal for reducing energy bills.
You can read more at How Do Radiator Valves Work? - A Complete Guide
﹢ My radiator is cold at the bottom. What's wrong?
This is usually due to sludge buildup, preventing hot water from circulating properly. A power flush or radiator flush can resolve the issue.
You can read more at Why is my radiator cold at the top/bottom?
﹢ My radiator is leaking. What should I do?
Turn off the valves to stop water flow, place a container underneath, and dry the area. Small leaks may be fixed with PTFE tape, but serious leaks require a plumber.
You can read more at How to fix a pinhole leak in your radiator and copper pipes
Specific Situations
﹢ How do I replace a radiator in a bathroom?
Consider upgrading to a heated towel rail, which provides warmth and dries towels. Ensure proper pipe connections and check if an electric option suits your needs.
You can read more at Heated Towel Rails - A Complete Guide
﹢ How do I replace a radiator with a different size?
If the new radiator is larger or smaller, you may need to extend or shorten the pipework. This requires extra work and may be best handled by a plumber.
You can read more at How To Replace A Small Radiator With A Large One
﹢ How do I move a radiator to a different wall?
Moving a radiator requires rerouting pipework, which can be complex. A professional should handle this to ensure correct installation and avoid leaks.
﹢ Can I have an electric radiator?
Yes, electric radiators are a great option, especially in spaces without a gas supply, such as attics, conservatories, or home offices. Unlike traditional radiators, they don’t require existing pipework, making installation straightforward and often more cost-effective than extending your central heating system. Simply connect them to a standard electrical outlet, and they provide efficient, controllable heat. However, for safety and compliance, an electrician should install hardwired electric radiators.
You can read more at Is An Electric Radiator Cheaper?
By understanding these frequently asked questions, you can better prepare for your radiator replacement project and make informed decisions.
Stylish radiators at TradeRadiators.com
If you want to choose a specific radiator stye for your home, rather than just leaving it up to the professional tradesperson, then make sure you check out the massive range at Trade Radiators.
Trade Radiators has been supplying the UK’s most comprehensive range of radiators, heated towel rails and electric heating options at trade prices for over a decade, becoming the largest independent retailer of our type anywhere in the UK in the process.
Whether you’re looking for a new designer radiator, or simply need a small accessory to help finish the installation, Trade Radiators has what you’re looking for.
All our products come with free delivery across mainland UK, with the majority of radiators qualifying for next day delivery, so you’ll get your order within 24 hours.
The radiators in our homes are incredibly important pieces of equipment and we heavily rely upon them to keep us warm, particularly in the coldest months. Radiators generally have a long lifespan, but inevitably after years and years of constant use, they can become less efficient and eventually need to be replaced.
Much of the UK's housing stock have radiators that are many decades old, so it's a very real possibility for many to buy a house with incredibly old rads that simply aren't up to the job. Years and years of water running through pipework and radiators can cause internal rust which sits at the bottom of radiators in the form of sludge. This rusty sludge makes your boiler have to work hard to get your radiators up to temperature and can cause unnecessarily high gas bills as a result.
A common symptom of an old, sludge-filled radiator is when it gets hot at the top by remains cool/cold at the bottom. If you've got old radiators that you think are suffering from this problem then it time to look into upgrading them.
DIY or professional?
If you have some DIY experience, then replacing a radiator is not in and of itself as difficult task. If you have a single radiator that needs replacing and you're confident you have the skills to replace it, then this is something you can do yourself and would certainly save you money on labour costs. You'd just need to pay the price of whichever radiator you choose.
However, if you have more than one radiator that needs replacing then it's probably worth your while calling in a professional. In many older homes, it might be the case that the pipes need rerouting to make better use of available space in order to accommodate the new radiators and this kind of job would be better dealt with by someone in the trade.
Additionally, if radiators haven't been replaced in a long time, the gas-fired boiler may also be very old and need looking at. A Gas Safe Registered Engineer will be able to inspect your boiler to see if it is still functioning safely and efficiently and can make any repairs or recommendations if necessary.
Please note, if you are replacing electric radiators, you must get a qualified electrician to fit them for the work to be legal. This is not a job you can do yourself.
Who chooses the new radiators?
Most professional tradespeople will be able to advise the best type of radiator for the room and will perhaps give you ideas you hadn't previously thought of. If you don't have any particular preference in terms of design and just want something that heats the room efficiently, then leaving it up to the tradesperson could be a great, low-stress choice.
But if you do have something special in mind then you may find it preferable to order your chosen radiator yourself and simply get the professional to install it. Many tradespeople have a favoured brand or style of radiator that they like to install and these may not necessarily be to your taste. Choosing your radiators yourself means you'll get exactly what you want and for a price you have control over before getting the labour costs from the professional.
What are the labour costs?
There are variables involved with replacing radiators that can affect the final cost, such as how many radiators need replacing, how large your home is and if pipework needs laying or re-routing. Another important variable that can affect the labour costs is where in the country you live. For example, a professional fitting a radiator in London is likely to be more expensive than in Carlisle.
The costs below are from Checkatrade who provide 'ballpark averages' on a per radiator basis
| Remove a small radiator | 1 hour | £80 |
| Remove and repair radiator | 1-2 hours | £125 |
| Remove and replace a double panel radiator | 1-2 hours | £200 |
| Replace a large radiator | 2 hours | £300 |
| Move a radiator | 2 hours | £275 |
A wide choice of radiators
If you want to choose a specific radiator stye for your home, rather than just leaving it up to the professional tradesperson, then make sure you check out the massive range at Trade Radiators.
Trade Radiators has been supplying the UK’s most comprehensive range of radiators, heated towel rails and electric heating options at trade prices for over a decade, becoming the largest independent retailer of our type anywhere in the UK in the process.
Whether you’re looking for a new designer radiator, or simply need a small accessory to help finish the installation, Trade Radiators has what you’re looking for.
All our products come with free delivery across mainland UK, with the majority of radiators qualifying for next day delivery, so you’ll get your order within 24 hours.
View Our Full Radiator Range
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