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Discuss Flow and return the wrong way around in the Underfloor Heating Forum area at

  1. Ams

    Ams New Member

    I would really appreciate your view on this underfloor heating set-up.

    I’m experiencing what sounds like a knocking noise from the manifold/pipework (can’t tell which) for a few seconds whenever the underfloor heating zones are switched on, so am wondering if it’s an issue with a valve or something.

    I’m also seeing that the temperature gauge on the return is always higher than on the supply side as shown on one of the photos (and all the flow meters have always been in the fully ‘red’ indication). I think this due to the fact that the flow and return seems to be the wrong way around ?

    I would be very grateful if you could take a look and confirm if the pipework all looks to be in the correctly fitted locations.

    I’ve attached a few photos of my manifold system – I’ve been trying to work out what each component does and how it works.

    Would appreciate any advice (not looking to carry out the work myself, but at least know what to look at first).


  2. Uheat – Wojtek

    Uheat – Wojtek Sponsor

    Good afternoon,

    it looks like a Polypipe manifold to me which has got the flow meters at bottom bar.
    The control pack is not Polypipe, looks like Rifeng Inta Eco Ecomix.
    What you need to do unscrew the manifold bars from the brackets and swap them so flow meters will be at the top of the manifold.
    At the moment pump is trying to push the water through the return bar where the actuators are and they need few minutes to be fully open.
    I've also done some research ref this mixing valve to ensure flow and return are connected properly and that seems to be fine (see image attached).

    That should resolve all problems.

    All the best,

    Wojtek Zareba @ Uheat UFH

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  3. Ams

    Ams New Member

    Thank you very much for taking a look at this and posting a reply so promptly.

    You're correct that it is an inta eco mixer but I couldn't see the arrow markings you've now shown too. The top rail is hotter than the bottom so that confirms the hot water is flowing through the pump upwards correctly, but I can see now that the rails is the wrong way round.

    The only thing I don't know is what make the manifold is as there's no markings on it that I can see but all the the other fittings look like Watts.

    Appreciate any other advice also.


    IMG_2979 2.JPG
  4. Uheat – Wojtek

    Uheat – Wojtek Sponsor

    I think is a Polypipe manifold. It doesn't make any difference to be honest, you can swap the bars around anyway.

    Uheat – Wojtek
  5. Ams

    Ams New Member

    Thanks for clarifying.

    One other question, once the bars are swapped around, how do set the flow rates to the correct level (are there any instructions anywhere ?) - how to determine what they should be also (based on length of piping laid ?).

    I've had the system in for almost 3 years now, but as it's been off all summer, I haven't had to put up with any issues, but know that this needs to be corrected now. Is there any possibility of the pump or actuators having been damaged as a result of the bars having been installed the wrong way around.

    Thanks again.
  6. Uheat – Wojtek

    Uheat – Wojtek Sponsor

    Good morning,
    I don't think the actuators became damaged but you never know.
    Pump - same again, difficult to judge.

    Flow rates - they will depends on circuit lengths.

    Many thanks,

    Uheat – Wojtek
  7. Ams

    Ams New Member

    Many Thanks again

    Would you know of a suitable installer/engineer in the Slough area - SL3 so I can get the rails swapped around
  8. Uheat – Wojtek

    Uheat – Wojtek Sponsor

    I haven't I'm afraid.
  9. Ams

    Ams New Member


    I was testing the system again just now, and noted that the 'banging' noise starts a minute or so after the zone is activated - at this point, the pump is already pumping as it has a green light, and so it seems that the noise starts when the actuator is actually opening whereas I would have expected it to be almost immediate if it was due to a delayed activator as described above.

    Could there be another issue for the banging also (water hammer).

    Appreciate the advice again

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