If you need to move your radiator position, extending radiator pipes is going to be one of your essential tasks. Working with central heating systems and radiator valves can be intimidating if it is your first time adjusting them. But if you follow our steps below, you’ll find how to extend radiator pipes and it is not as complicated as it first appears!

Undoing a Radiator

Why Extend Radiator Pipes?

There are various reasons for needing to extend the pipes to your radiators such as allowing for different skirting boards to be put in, a room design to be readjusted, the installation of a new radiator model, or for an area to be renovated. Choosing to extend your pipes may help you to avoid having to pull up floorboards and create any unnecessary damage to your room decor.

How to Extend Radiator Pipes?

If you are looking to adjust the height of the positioning of your radiator, you will need to work out how to extend the length of the existing water pipes to keep the equipment functioning at its optimum level. Once you have gathered all your equipment together, it is a surprisingly straightforward process to extend radiator pipes.

What You Need

  • Tape Measure
  • Pipe Extensions (Copper/ Plastic)
  • Hose Pipe
  • Push-fit Joints
  • Pipe Cutter (amazon link – opens in a new tab)
  • Pipe Deburring tool
  • Bowl/ Towel

Step 1 – Take Your Measurements

Your first step before you do anything is to take accurate measurements that will guide all your other actions. Initially, you should measure the radiator pipes to ensure you cut the right size extension pieces. You will also need to measure the current distance of the radiator from the floor as well as the height you will want the radiator to sit at when the process is finished. Most radiator pipes are copper although some are now made of plastic, and both can be extended without any real hassle. Now, if you are already an accomplished DIY hobbyist and know how to solder, you can go ahead and solder the joints. In truth, like most people, you may not have the required experience, or the tools so we recommend using push-fit joints.

Once you have all your measurements you can head to the DIY store to buy your pipe extensions.

Step 2 – Shut Down and Drain the System

Your next step to get the process started is to shut down the radiator system and let it cool down completely, so you do not run the risk of any burns or flooding when you begin to work on the pipes. To start draining the radiator pipes, go to the radiator that is furthest from the boiler and attach a hose to the drain valve. Then go to the highest radiator in the house system and turn the bleed valve on the side so that it becomes loosened. This will allow air to enter the pipes and will help to force the water in the system out. It is essential that you properly drain the system before you begin or else you could find yourself facing a DIY disaster as soon as you begin to work on the pipes.

Note: Draining down a system can take anywhere from 30 mins to a few hours.

Step 3 – Measure and Cut Your Pipe Extension

Next, you can use a pipe cutter to cut the new parts of the pipe which will be fitted onto the existing pipe and extend its length. Then you can measure and cut across the part of the pipes where your new pipe extensions will join the existing pipe system. Now you will need to ensure that the end of the cut pipe is smooth, and all of the sharp edges (burrs) have been removed. De-burring tools are available, but a file will do the job if required. Be sure to smooth both the inside edge and the outside edge of the pipe to ensure a clean joint.

Note: When using push-fit joints on copper, it’s important that your pipes are cut cleanly, so ensure you use a pipe cutter rather than a hacksaw.

Step 4 – Add the Extension

Once you have cut through the existing pipes at the proper height, you can move the radiator temporarily to allow you to affix the new extension. This should be a two-person job to ensure your safety and that the radiator isn’t damaged by any drops or bumps. Once the radiator has been set down safely, you can take your coupling or push-fit joint to the part where the existing and new pipes meet.

Step 5 – Re-Fit the Radiator

Remove any dirt, grime, or associated residue with a clean damp cloth, and then you are ready to re-fit your radiator. As mentioned above, this is best done with 2 people to ensure that you do not damage any of your new pipework when fitting. If you have any concerns about the safety or workability of the work you have done, it will always be better to get someone with an expert eye to come in and check over your work.

You may be wary of having to do the whole process over again or pay someone else to, but the cost and damage involved if you leave a faulty radiator to operate uncorrected should provide more than enough motivation!

Step 6 – Check for Leaks

Now you are ready to close the drain valve and the bleed valve you opened earlier and re-pressurise the system and check for leaks. If you do in fact have a small leak, you will need to recheck your work. This can be laborious and frustrating, so it is important to take care and get it right the first time.

Note: After removing a radiator, you may need to re-balance the system.


Now that you know how to extend radiator pipes, it’s time to get started on the project! Make sure you have all of the supplies and tools you need before beginning. Remember to use a pipe cutter and de-burr the ends for clean joints. If you run into any problems during the process, be sure to consult an expert. With these tips in hand, you should be able to complete this project with ease. Have fun and stay warm!

How to Extend Radiator Pipes Infographic

Plumbing Wizard Tips

“Make sure to measure twice and cut once to ensure the best possible accuracy!”

“When draining the system, take note of the colour of the water – if it is a murky brown colour, it would indicate that you have a sludge build-up too!”

“Whilst you are draining the system, this would be a great opportunity to flush the entire system which should be done approximately every 5 years!”

“Make sure that you match the right fittings for the pipe you are working on – for example, use copper fittings with copper pipes and chrome fittings with chrome plated pipes!”

Frequently Asked Questions

Can I use push fit on chrome?

Yes, chrome push-fit joints can be used on chrome although the chrome plating will need to be removed from the end of the pipe to ensure a watertight seal.

How far should a radiator pipe be from the wall?

As a guide, radiator pipes should be approximately 15mm from the wall to prevent the wall from becoming hot or your décor from being damaged.

Can flexi pipe be used on radiators?

Yes, flexi pipe can be used on radiators although this option is far less attractive than clean, straight pipework in copper or chrome.


Lee Pearce is not just a master plumber; he’s a veritable Plumbing Wizard. With over 30 years of experience in the trenches of pipes and drains, Lee has become the go-to sage for DIY plumbing, saving homeowners thousands in potential call-out charges. As the founder of Plumbing Wizard, he’s dedicated to demystifying the complexities of home plumbing, offering easy-to-follow advice that stands the test of time and pressure. His online blog is a treasure trove of tips, tricks, and tutorials that empower everyday individuals to take charge of their home’s plumbing health. Lee’s practical wisdom is not just about fixing leaks; it’s about imparting confidence and self-reliance. When he’s not writing or elbow-deep in a plumbing project, Lee is passionate about educating the next generation of DIYers, ensuring that practical skills are passed down and preserved.

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