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Discuss Combi install, Use of one tap at a time in the Plumbing Forum area at

  1. Griggers

    Griggers New Member


    We have just had a Vaillant ecoTec plus 832 installed. This is a 32 kW rating with a 13 liters per min flow rate. This was the recommended spec from the installer. But it would appear that only one tap can be used at a time (this is worse upstairs). Filling the bath for example means that any other hot tap is reduced to next to nothing. I understood from the installer that this boiler should cope with running two outlets at one?

    Many Thanks
  2. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Standard combi won't run more than one outlet

    Sorry to say will never happen/ cope with two outlets at the same time
    • Agree Agree x 2
  3. Griggers

    Griggers New Member

    Many Thanks for the info.. Ok bit of a trade off then..
  4. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Yep your trying to split around 10lpm between two outlets / more which will always be poor
  5. scott_d

    scott_d Plumber GSR Top Contributor!!

    What's your incoming flow?
    Stop tap fully open, and the one in the road?
  6. Chuck

    Chuck Active Member

    I suspect the problem may lie with the mains supply or pipework.

    Measure the delivered flow to the bath, e.g. by timing how long the hot tap takes to fill a bucket. Compare that with the 13 litres / min that your boiler is supposedly capable of delivering.

    If the system has been converted from a traditional storage tank, the pipe sizing may allow the bath tap to starve the other taps in the building. If this is the case, the cheapest 'solution' is just to open the bath tap enough to get 6.5 litres / min leaving capacity spare for the other taps.
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