There are several reasons why you might want to take a central heating radiator off the wall.
Maybe you are fed up with struggling to wallpaper behind it or perhaps it is rusty, and you need to replace it. You might find that it no longer gets hot at the bottom even though you bleed it regularly. There could be a buildup of sludge that you need to wash out.
Changing the radiator isn’t as difficult as you might think if you know how to cheat. The method you will learn here is the quickest and most convenient way that does not impact the rest of the central heating system. Of course, the fault might not lie with the radiator. If you suspect a breakdown, you could always ask the opinion of an expert.
If you have a combination boiler, the process is a little more difficult than if you have a standard one, but if you are a capable DIY fan, you will still be able to do it.
Here is the process I use:
- Close the valves on each side of the radiator by turning them in a clockwise direction.
- Place a shallow bowl under the big nut that connects the valve to the radiator.
- Using a spanner, slowly unscrew one of the nuts, If you are facing the end of the radiator, turn the nut in a clockwise direction with a spanner. The nut is part of the radiator, not the valve.
- Open the bleed screw at the top of the radiator. The water won’t come out until you do this because it’s the flow of air that forces the water out.
- When water starts to dribble out, catch it in the bowl.
- Wait unit the bowl is full and tighten the valve nut until the flow stops. Empty the bowl and begin the process again.
- When the water stops coming out, undo the nuts completely to release the valves.
- Lift the radiator off the brackets and carry it outside without tipping it, or you will drop filthy water on the floor.
That wasn’t so hard, was it? Here is the process for replacing the radiator.
- Hang the radiator back onto the wall brackets.
- Attach the valves with the large nuts.
Refilling And Bleeding A Standard System
- Open the valves on each side of the radiator.
- Open the bleed valves at the top and wait until water starts to spit out.
- Close the bleed valves.
Refilling And Bleeding A Pressurised System
- Ask an assistant to stand by the boiler and watch the pressure gauge. When it starts to drop, they must open the filler tap to refill the system and compensate for it. It will only happen slowly.
- Open the bleed valve at the top of the radiator.
- Open one of the valves slowly until you hear water trickling into the radiator. The pressure will start to drop so your assistant must open the filler tap slightly.
- Wait until water spits out of the radiator and close the bleed valve.
- Wait until the pressure is stable and close the filler tap by the boiler.
- Open the second valve on the radiator.
If your radiator doesn’t get hot after you replace it, there might be an airlock. To fix it, close the valves on all of the others, and let the pump force the air out of the pipes to the unit on which you were working.
You may also need to bleed air out of the pump. There is a screw valve on it that you loosen until water spits out. On combination systems, the pump is usually inside the housing of the boiler.
I think that covers it guys; anybody can do it. If something goes wrong you can always call a plumber; it isn’t the end of the world. Make decorating easy by removing the radiators. The more you take off, the easier the process becomes.
Video: How to Remove and Replace a Central Heating Radiator
Video Credit: dereton33
Infographic: DIY Radiator Advice
Infographic Credit: Trads Cast Iron Radiators