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Double radiator advice

Discussion in 'Plumbing and Central Heating' started by Brian Greenhalgh, 21 Mar 2021.

  1. Brian Greenhalgh

    Brian Greenhalgh

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    We had a old double rad that was from the 70s 1500mm and we had a extension built and needed a radiator in it so what I did was took the the old radiator out and putting a single 1400mm and a single 1200mm in the extension I run the feed into the 1400mm out then into the 1500mm the 1500mm is not getting as hot but the pipe to the rad is very hot
     
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  3. oldbuffer

    oldbuffer

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    1. Have you rebalanced the system since adding the new radiator(s)?
    2. Have you now got a 1,500 double, a 1,400 and a 1,200 (singles) all running off the original pipework for the 1,500 double?
    3. Have you bled all the radiators?
     
  4. Brian Greenhalgh

    Brian Greenhalgh

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    Sorry for being stupid rebalanced no sure both radiator are single and running off original pipe work and yes bled all radiators
     
  5. oldbuffer

    oldbuffer

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    1. Look up balancing to see how it's done. Long, boring, job I'm afraid.
    2. I'm afraid I don't quite understand what you have done. Is it:
    2a. Completely removed a 1,500 double and run it feed and run pipes to a 1,400 single then on to a 1,200 single? OR
    2b. Left the 1,500 double in place and added one 1,400 single and one 1,200 single run from the 1,500's feed and return pipes?
     
  6. Brian Greenhalgh

    Brian Greenhalgh

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    Yes I have removed 1500 double and put feed into extension which has 1200 then run it into 1400 then out to the return pipe
     
  7. Brian Greenhalgh

    Brian Greenhalgh

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  8. oldbuffer

    oldbuffer

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    Should go:
    Removed 1500 flow to new 1200 flow to new 1400 flow.
    1400 return to 1200 return to removed 1500 return.

    If you have gone 1500 flow to 1200 flow, then 1200 return to 1400 flow, then 1400 return to 1500 return you have effectively created a part one pipe system. Not likely to work very well, as the water coming out of the 1200 and into the 1400 will be 20 degrees (or thereabouts) cooler than it should be.
     
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  9. oldbuffer

    oldbuffer

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    Our messages crossed. You need to re-pipe it.
     
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  11. Brian Greenhalgh

    Brian Greenhalgh

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    So should I Tee in to 1400 and the feed run into the 1200 then back to return
     
    Last edited: 21 Mar 2021
  12. lostinthelight

    lostinthelight

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    You have the rads plumbed in series when they should be in parallel.
    Think as, the flow and return going to the 1200 and teeing off them for 1400
     
  13. Brian Greenhalgh

    Brian Greenhalgh

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    Does it matter which pipe to tee off from the feed or the return to the 1400mm
     
  14. lostinthelight

    lostinthelight

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    Doesn't make any difference as far as I'm aware , I just fit the Trv on the most airy side but these days good ones seem to be bidirectional anyway.
     
  15. Brian Greenhalgh

    Brian Greenhalgh

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    So it should be fine to tee off to the 1400mm on the return pipe
     
  16. denso13

    denso13

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  17. Terrywookfit

    Terrywookfit

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    You need to tee off Both pipes that feed the 1400 and pipe them to the other rad.
    A flow and return to each.
     
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