Bathroom heating and radiators

How to Fit & Replace a Radiator

Radiators are one of the most reliable fixtures of any home but they sometimes need replacing, either for improvements in efficiency or faults.

Removing and replacing radiators that aren’t working properly will save you energy. Ensuring that your central heating is working efficiently is a must, not just for your own comfort, but also for your bank balance.

Wear and tear are unavoidable, but how do you change a radiator? Well, Plumbworld is here to help walk you through the process. We’ll discuss why you may need to change a radiator, how to remove it and then how to fit a replacement.

Read on to find out how to remove and replace a radiator…

Why would I need to replace a radiator?

DuraTherm Horizontal Oval Tube Single Panel Designer Radiator - 600 x 1200mm

Replacing your radiator depends on the quality of your installation, the unit itself, and the upkeep of the radiator - including its age.

Learn more about radiators at Plumbworld

If you are noticing uneven heat distribution or a total absence of heat, then the radiator is likely finished and needs replacing. Radiators can be taken for granted in that they can last for decades but they rarely have one huge failure, their efficiency declines over a while.

Some of the main reasons for replacing a radiator include:

  • Rust, corrosion and blockages for the radiator that can no longer be fixed
  • Radiator is no longer efficient compared to those on the market
  • Need to comply with quality and safety regulations
  • New home, so you may want new fixtures
  • Improve the visuals of your radiators to match a room design
  • Improvements in efficiency, both heat and water

How to Change a Radiator

DuraTherm Traditional Colosseum Double Bar Column Radiator - 600 x 828mm

Replacing a radiator is usually reserved for a competent DIY fan, who is confident and able to hand plumbing tasks.

Read more: A Guide to Bathroom Heating

Before you do get started, it will help to check the walls against which your radiator sits. Are there any cracks or crumbling plaster? If there are, you may need to make repairs before you fit your new radiator.

What equipment will I need for changing a radiator?

Some of the kit you’ll need when it comes to removing and replacing your radiator includes:

  • Spirit level
  • Radiator key
  • Pipe cutter
  • Adjustable pipe wrench
  • Adjustable spanner x 2
  • Tape measure
  • Bucket
  • Dust sheet
  • Pipe tape
  • Screwdriver
  • Drip tray

Remember: If the wall is solid masonry, you’ll have a wider choice of replacement radiators to choose from than if it’s plasterboard.

How to Remove a Radiator

DuraTherm Horizontal Single Flat Panel Designer Radiator - 600 x 1212mm

Turn off the water supply

  • First things first, like with all plumbing jobs, turn off the water supply - the central heating - and allow the water in the system to cool. 

Close the valves

  • At either end of the radiator, you’ll need to close and turn off the valves. One is the manual control valve that turns the heat on and off. Turn it off by rotating clockwise.
  • At the other end is the lockshield valve - it controls the flow through the system. Take off the protective cap and turn the square top piece clockwise.

Tip: Count the number of turns needed, as the valve should be opened by the same amount when you replace the radiator.

Drain the old radiator

  • Place a bowl, tray or bucket under the manual control valve. Grip the valve with an adjustable spanner and hold it steady while you use another to loosen the nut on the valve (the air bleed valve) that is connected to the radiator.
  • Use a radiator key on the top edge of the radiator, to slowly vent any trapped air out of the radiator.
  • Use an old rag, cloth or towel to catch any drips from the valve and stop them falling on your flooring. Continue draining the water from the radiator until the flow of water stops.

Remove the radiator

  • Once the radiator is drained, you can loosen and undo the nut that connects the lockshield valve to the adaptor in the radiator.
  • You may have to push the central heating pipes and valves outwards to free the radiator connections.
  • Lift the radiator up to remove it from the wall brackets. Get some help for this bit, it can be tricky.
  • There may be some water left in the bottom of the radiator, so tilt it and drain into a bucket. The water may be dirty, so place the radiator on old towels or sheets.
DuraTherm Traditional Colosseum Double Bar Column Radiator - 300 x 1008mm

How to Fit a Radiator

It’s likely that your existing brackets won’t be compatible with the new radiator, so you’ll need to unscrew them. Therefore, you may have to fill any gaps left from the previous fixing holes.

Tip: Try attaching reflective radiator tape to the wall behind where the replacement radiator will hang. This will bounce heat back into your room and help lower your heating bill.

Drill for new brackets

  • Before drilling into the wall, you’ll need to make sure you’ve checked what’s behind it with a digital detector. 
  • They will let you know whether there are any pipes, cables or studs where you’re planning to drill. Run it over the surface and it’ll tell you if there are any hazards.

Fit the new brackets

  • Once you’ve finished drilling, fit the brackets to the wall and you will be able to fix your radiator to the brackets. Di so in accordance with the manufacturer's instructions.

Tape and install your valves

  • Get some PTFE or plumbing tape and wrap a 20cm length around each valve thread.
  • So it’s easier to make adjustments, It's best to install your valves before attaching your radiator to the wall.
  • Once you’ve done that, open both valves fully to allow the radiator to fill with water from the central heating system.

Lift and hang the radiator

  • Lift the new radiator up onto the wall brackets. 
  • Check the radiator is hanging straight and then you can tighten the fixings. 
  • This is a two-person job. It’s much easier and less stressful if you have someone to help you.
DuraTherm Vertical Double Flat Panel Designer Radiator - 1600 x 304mm

Open the valves and allow water in

  • Make sure the manual control and bleed valves are fully open and open the bleed valve to allow water into the radiator.
  • Once the radiator has stopped ‘gurgling’ and is full, open the lockshield valve by the same amount of turns as you needed to close it earlier.

Final checks

  • Check all the joints and sealings are dry and waterproof. Tighten if necessary and then you can turn on your central heating system back on.
  • Finally, perform last checks to ensure no water is leaking out and that the radiator is evenly getting hot.

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Don’t forget to check out the rest of our blog for more bathroom advice…

How to fit a Shower Enclosure | Best Bathroom Designs for Living on Your Own | Design Inspiration: Contemporary Bathroom Design Tips


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