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Replacing Rad - help with sizing and tails needed

Discussion in 'Plumbing and Central Heating' started by NeilPalfreyman, 7 Jun 2021.

  1. NeilPalfreyman


    26 Dec 2012
    Thanks Received:
    United Kingdom
    Hi all,

    I'm planning on replacing the old radiator shown in the pic below and have a couple of dumb newbie questions that I hope you can help me with.


    The first is on dimensions. The old rad is 1350mm by 690mm, measured across the radiator panel. The replacement I'm looking at is this one:


    Which is described as 1400 by 600

    So my first dumb question is about the width. I don't want to drain down the system or replace the lockshield or TRV and there's not much "wiggle room" on the existing pipes. The replacement is described as 1400mm wide.

    Is this dimension the width of the new rad panel, or the width of the pipe centres? (My old rad is 1400 from pipe to pipe.)

    Second question is about what tool(s) I need to remove/re-use the existing tails from the old rad. Here's a couple of photos:
    IMG_20210607_074243.jpg IMG_20210607_074259.jpg

    Any other tips or advice about "gotchas" and how to get around them appreciated!

    Thanks in advance!
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  3. Baths'N'Gas


    31 May 2009
    Thanks Received:
    United Kingdom
    Go for a smaller radiator than 1400, and get some radiator tail extensions or long radiator tails and cut them down to size, if you do want the 1400 rad then the pipes will need altering
  4. oldbuffer


    6 May 2010
    Thanks Received:
    United Kingdom
    1. The new radiator will almost certainly have the across width pipe centres at the same dimension as the panel width, in your case 1,400 mm.
    2. The new radiator will have pipe centres 66 mm from the flat surface to which the brackets are fixed. i.e. the wall.
    3. You will need to measure:
    3a. The distance from the wall to the centre of the existing radiator's inlets.
    3b. The distance between the across the width centres of your existing radiator. Whi9le it is hard to see that point for the non-TRV end, it will be symmetrical with the TRV end, which should be measures from where the tail with the square chrome nut enters the body of the radiator.
    4. You are going to have some difficulty getting that radiator off without draining the system. I'd suggest removing the non-TRV end first, which is on a union fitting, then the TRV end, which looks like a compression fitting.
    5. To remove the non-TRV end tail you will need a special tool. screwfix 1147 might do it, but the fittings aren't universal, so you might need a multi-purpose plumbing key.
    6. To remove the TRV end tail you will need a suitable spanner for the square chromed nut. An adjustable is probably your best bet.
    7. Unless you can get a radiator to exactly match the dimensions of the old, you are going to have to adjust the pipes, which will mean cutting the skirting boards. If you are OK on the distance from the wall, consider getting a narrower (but perhaps taller) radiator and using extension pieces to bring the tails out as required. Don't use telescopic extensions.
    8. If I were doing it I'd drain down, replace the radiator and both valves, and adjust one end of the pipework as necessary. You are giving yourself non-trivial complications.

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