How to Replace a Radiator

Replacing a radiator? It’s easier than you might think. Many come with everything you need to fix them to the wall, giving you one less thing to worry about. As for the process, we’ve put together this handy step-by-step guide to help you replace yours.

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Choosing the right radiator

When choosing your new radiator, firstly consider the pipe centres. It’s always a good idea to select a replacement radiator with pipe centres that match your existing pipework. If this isn’t possible, a plumber will need to reposition your new valves.

You’ll also need to check what your wall is made out of. If it’s solid masonry, you have the choice of any size or style of radiator as the wall can hold more weight. If it’s plasterboard, you should use a stud detector to identify where the wall supports are; these are what you’ll need to screw the radiator’s brackets into. If this isn’t possible, we recommend using wall plugs.

As there are many different styles of radiators available, it’ll be easy to find one that fits in with your décor. Horizontal radiators are the most common design, but if you’re working with a small space, a vertical radiator might be a better option. It’s also worth considering what your chosen radiator is made from as some materials (e.g. aluminium) heat up quicker than others, and some (e.g. mild steel) are more affordable than others. This way, you can find an option to suit your preferences and budget.

Lastly, you have the choice between single or double panel radiators, with double panel designed to provide 40-80% more heat output. In terms of aesthetics, column radiators provide a more traditional look, and flat panel radiators are more contemporary and minimalistic.

Replacing your radiator

It’s time to prep for replacing your radiator. Below you’ll find all the tools needed for a successful replacement, as well as a step-by-step guide on the process.

You will need:

New radiator with valves and fixings

Adjustable wrench

Radiator key

Trays and towels (for water spillage)

PTFE tape

Turn off your heating system via the boiler or by using the thermostatic radiator valve. Then, you’ll need to isolate the radiator by closing off each valve. As you’re turning the valves, you should count the number of turns it takes to switch them off as you’ll want to install the new radiator at the same flow rate.

Use a spanner to loosen the nut on the radiator valve, making sure to hold the valve tightly at the same time. Next, use a radiator key to slowly let trapped air out of the top of the radiator. This allows the water to flow from the manual control valve. You should place bowls and towels under the radiator to catch any excess water. Leave it to bleed until the water stops running.

Once the water stops, remove the radiator from the wall and tip it sideways to release any remaining water. And unscrew the remaining brackets from the wall.

Fix the new radiator’s brackets to the wall, following the manufacturer's instructions, before sliding the radiator onto the brackets, making sure it’s level and secure.

Wrap PTFE tape around each valve thread to create a tight seal, and install your valves before securing your radiator to the wall. For guidance, line up the new radiator with your existing pipework and tighten the nuts with an adjustable wrench. To allow water to flow into the radiator, fully open both valves. Once filled with water, open the lockshield valve by the same amount of turns you counted earlier.

Once the installation is complete, you’ll need to bleed and rebalance the new radiator. For advice on these steps, check out our guides on bleeding and rebalancing a radiator