Posting a message to the forum will remove the above advertisement
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. Checkout our Plumbers Insurance area - heavily discounted Public Liability Insurance and Van Insurance specifically designed for plumbers.

Discuss Salamander Homeboost, Hot water coming out of cold tap in the Plumbing Forum area at UKPlumbersForums.co.uk.

  1. David Medlycott

    David Medlycott New Member

    Hello

    I have a Vaillant Ecotec Plus 835 with a Salamander Homeboost pump fitted to the mains supply underneath the boiler.

    If I switch on the cold tap first I get cold and if I switch on the hot I get hot, the booster kicks in but doesn’t switch off, but..

    If I switch on the hot tap first the booster fires; does not switch off when I close the tap, then if I open the cold tap hot water flows?

    If I close one of the isolation valves the pump stops as expected, and if I switch the pump off completely the taps work correctly.

    My gas engineer says it’s bizarre and can only suggest replacing the pump, Salamander say they don’t think there is anything wrong with the pump as it stops when the isolation valve is turned. And neither can understand why hot would come out of the cold!?

    Any suggestions would be appreciated!

    Thank you
    David
     
  2. Level 2 student.

    Level 2 student. New Member

    "If I close one of the isolation valves the pump stops as expected, and if I switch the pump off completely the taps work correctly."

    With this info, Id say try changing the pump.
     
  3. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    Get salamander in if they’re sure nothings wrong
     
  4. David Medlycott

    David Medlycott New Member

    Out of warranty
     
  5. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    They will still offer a repair service
     
  6. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    • Like Like x 1
    Last edited by a moderator: Mar 20, 2019
  7. Craig Watson

    Craig Watson Plumber GSR Top Contributor!!

    Id agree with salamander on this one. If the pump stops when isolated, that proves the pumps flow/pressure switches work.

    Where in relation to the stop tap is the home boost fitted?

    I'd also be asking your installer why he's fitted an 835 which is capable of 14ltm of hot water delivery, when the home boost is restricted to 12ltm.
     
  8. David Medlycott

    David Medlycott New Member

     
  9. David Medlycott

    David Medlycott New Member

    Someone has suggested that maybe one of my mixer taps or shower thermostatic controls could be worn and allowing cold into the hot so when the hot is switched off cold could still be sleeping through..?
     
  10. David Medlycott

    David Medlycott New Member

    The booster is fitted 1m below the isolation valve and boiler.

    Ground floor kitchen tap doesn’t get as hot as 2nd Floor bathroom?

    The pump is fitted because my 3rd floor shower struggles with pressure, Ground Floor is adequate.
     
  11. Craig Watson

    Craig Watson Plumber GSR Top Contributor!!

    So the home boost only feeds the hot water? To have installed this you must have poor cold mains flow/pressure? Was the static/dynamic pressure and flow rate tested before installing the pump?
     
  12. David Medlycott

    David Medlycott New Member

    Yes, And has been installed for three years with no dramas.
    I don’t know whether the pressures and flow rates were tested prior to installation, but I asked for it to be installed to help with my top floor shower.
     
  13. Mastermixlee

    Mastermixlee GSR

    With only hot water being fed from the pump If there is a mixer that is passing it is possible that the pump pressure when running is enough to force through the passing mixer thus keeping the flow switch activated. But when under standing pressure not enough to operate the flow switch in the pump.

    Which would explain the hot water Coming through the cold tap too. The boosted pressure hot would be flowing through a passing mixer and forcing down the cold pipework.

    So if possible to turn off isolation valves to mixer taps to identify which one is at fault then go from there.

    And depending on system config I'd consider putting check valves on cold feeds to taps too.
     
    • Agree Agree x 1
  14. David Medlycott

    David Medlycott New Member

    Thank you for your reply. Much appreciated.
    Will give it a go and get back to you
     
  15. Craig Watson

    Craig Watson Plumber GSR Top Contributor!!

    I Agree with mastermixlee and is the reason for asking where the pump was located. The manufacturer do recommend that when using their home boost to solely feed the hot water supply, non return valves should be fitted to mixer taps showers as the static/dynamic pressures most likely won't be equal.
     
Loading...
Similar Threads - Salamander Homeboost water Forum Date
Salamander pump not starting up Bathrooms, Showers and Wetrooms Apr 9, 2019
Salamander rp100 tu pump advice Plumbing Forum Jan 30, 2019