Danfoss 3 port valve wiring

Discussion in 'Plumbers' Talk' started by dcox, Oct 13, 2021.

  1. dcox

    dcox Screwfix Select

    024E6764-974F-4B01-BCB6-5E2FA02462EA.jpeg 1B71A854-79DA-417F-A0CB-7B2483353E1D.jpeg

    Wiring is not my strong point. A customer with an open vented boiler has hot water but no heating. I suspect the danfoss 3 port valve. There are 4 wires: orange (switched live), grey (hot water off), brown & white (heating on) and blue (neutral).

    I was expecting the orange to become live once the valve had moved to the heating position but that’s not the case. It does become live and fire the boiler when hot water is selected.

    Am I right that the orange should become live when either is selected?

    The black wire on the left is the 3 port.

    Thanks!
     
  2. terrymac

    terrymac Screwfix Select

    Yes the orange wire is switched live to boiler.
     
  3. dcox

    dcox Screwfix Select

    Thanks. The brown/white wire becomes live when the programmer calls for heat so it must be a fault with the valve, right?
     
  4. terrymac

    terrymac Screwfix Select

    Brown/ white wire ?
    There should be blue ,green/ yellow ,white, grey ,and orange ( 5 in total) from MP valve to wiring centre ??
     
  5. dcox

    dcox Screwfix Select

    No - the danfoss HSA3 only has four as in my first post.
     
  6. kiaora

    kiaora Screwfix Select

    hi.
    if it helps, i put this drawing together, (leaving out neutrals and earth, for clarity.)
    how y plan works

    good luck
    peter
     

    Attached Files:

  7. dcox

    dcox Screwfix Select

    Thanks for that, Peter. I assume the orange will serve the same purpose with the different Danfoss wiring.
     
  8. kiaora

    kiaora Screwfix Select

    yup.
    its almost always orange for boiler live
     
  9. kiaora

    kiaora Screwfix Select

    if you follow the wires from the program, i think you can solve any problems,
     
  10. kiaora

    kiaora Screwfix Select

    also
    im not sure but the valve you have, may not be spring return.
    its powered both ways, is it hot water priority ? or flow share, ?
    this diagram is for spring return, but should help figure it out
     
  11. terrymac

    terrymac Screwfix Select

    So it doesn't have an earth ?
    Can't say I have ever come across that before.
     
  12. kiaora

    kiaora Screwfix Select

    perhaps it's time to swop valve to mid position spring return ?
     
  13. Mike83

    Mike83 Screwfix Select

    5C4BAA8B-D3BC-429F-90C1-2B45CBF24129.jpeg
     
    kiaora likes this.
  14. dcox

    dcox Screwfix Select

    The brown & white gets 240v when the controller calls for heat. Then what? I'd normally expect the orange to become live and connect to the boiler switched live but the diagram suggests the orange is just HW.
     
  15. Mike83

    Mike83 Screwfix Select

    Had a quick look online.
    Found this.
     
  16. Mike83

    Mike83 Screwfix Select

  17. heatyman

    heatyman Well-Known Member

    HSA 3 is mid position spring return.
    The orange will be live in HW only by backfeed from cylinder stat. Only other thing to check is that the grey wire is live when heating only selected.
     
    dcox likes this.
  18. dcox

    dcox Screwfix Select

    Thanks for that - looks like the setup they have. Would you agree that the grey wire out of the 3 port should become live if the valve is working properly (when the brown/white call for heat is live)?

    Looking at the diagram, the grey doesn’t seem to go anywhere other than link to the cylinder stat off via the broken black line. What would trigger the boiler?
     
  19. dcox

    dcox Screwfix Select

    I haven’t done that - was expecting it to be the orange wire.
     
  20. heatyman

    heatyman Well-Known Member

    The grey wire is a live feed to the switch in the actuator. normally this is fed from the HW off terminal in the programmer and the satisfied contact on the cylinder stat. When HW only is selected, the orange will be live as it is backfed from the boiler/pump connection that is fed from the cylinder stat demand contact.
     

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