How to fit a new radiator


Here are some simple steps for a successful radiator installation to help you decide whether this is one for you or the professionals.  
How to fit a new radiator

Making sure your central heating is working efficiently is essential for your comfort AND your pocket. Not sure whether you can tackle fitting a new radiator yourself, or would rather sit back and get a plumber in?

Here are some simple steps for a successful radiator installation to help you decide whether this is one for you or the professionals.

Replacing a radiator isn’t too difficult provided you follow these instructions to avoid any issues to your system and messy water damage.

Should I get a new radiator?

The performance of radiators declines over time, and wear and tear is unavoidable. If you start to notice uneven heat distribution, or lack of heat entirely, it’s likely time to change.

You may also want a replacement due to:

  • Rust, corrosion or blockages that can’t be fixed
  • No longer efficient versus to newer ones on the market
  • To comply with safety regulations
  • Cosmetic/improving visuals and design of room
  • To improve water and heat efficiency

Replacing the same size radiator

The easiest way is a like-for-like replacement; meaning finding one that is the same size as your old one.

To find the same size replacement, make sure you measure using the ‘pipe centre’ number. That’s the distance between the two valves on each end. Measuring along the top of your radiator will not give you an accurate reading of the radiator size.

Also pay attention to the depth to avoid any issues connecting it to the pipes.

Before you get started, check the walls first for any cracks or crumbling plaster as you may need to make repairs before you fit your new radiator. If the wall is solid masonry, you’ll have a wider choice of replacement radiators to choose from than if it’s plasterboard.

Replacing a different size radiator

If you want to change the size or style,  you’ll need to reorient your new valves. You need to be sure someone knows what they’re doing – it’s best to get a plumber to do this.

What do I need to remove a radiator?

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

How do I remove a radiator?

  1. Turn off the water supply

The first thing you need to do is turn off your central heating and water supply. Make it has completely cooled down before you do anything else.

  1. Close the valves

Then, you need to isolate your radiator by closing off the valves located at both ends.

At one end, you will have your manual control valve or a thermostatic valve. Turn this clockwise until it it’s zero or off.

At the other end will be your lockshield valve. Pull off the plastic cover and turn the square shaft clockwise with an adjustable spanner. Note down how many turns you made, so that you can reset the new radiator at the same flow rate after you’ve fixed the radiator and need to re-open this valve.

  1. Drain the radiator

Next, release all the water out of your radiator . You will find a connection at either end of your radiator – this one looks like a nut. Place a bowl and towel down underneath it, ready to catch the water.

Using a spanner, turn the nut away from you a little to loosen it. You may need to hold the body of the valve with a second spanner or pipe wrench to stop it turning and buckling the pipe.

Use a radiator key on the top edge of the radiator, to slowly vent any trapped air out of the radiator. When the tray is almost full, retighten the swivel nut and empty the tray into a bucket.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 until the flow of water stops.

  1. Remove the radiator

Once all the water has drained out, remove it from the wall. You might need to pull the pipes out slightly at the sides before lifting it up. Radiators can be hefty so you may need a hand. Lift the radiator from its brackets and tilt to drain any remaining water. The water may be dirty, so place the radiator on old towels or sheets.

It’s likely that the existing brackets aren’t compatible with the new brackets, so you’ll need to unscrew these.

How do I fit a new radiator?

  1. Fit new brackets

Check what’s behind the wall with a digital detector first before drilling into the wall to avoid any nasty surprises. Always measure up according to the manufacturers instructions when fitting the brackets.

  1. Tape and install valves

Before you attach your radiator to the wall, wrap 20cm plumbing tape around each valve thread. Open the valves fully to allow it ti full with water from the central heating system.

  1. Fit the radiator

Fix your radiator to the brackets, checking that it’s hanging straight before tightening the fittings. This is best done as a two person job.

  1. Close the bleed valve and reconnect the water piping and valves

Do this before you switch on your water supply. Once it’s stopped ‘gurgling’ and is full, open the lockshield valve by the same amount of turns as you needed to close it earlier.

  1. Do 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.

Keep your sun shining

PlusHeat offer extensive home emergency cover so you can protect your home (and your wallet!) when things go wrong. We offer 24/7 advice and support with boiler and central heating, plumbing, electrical and drainage cover. Contact our friendly team on 0808 164 2892. We’re here to help!