Dishwasher problem

Discussion in 'Plumbers' Talk' started by PandA3, Mar 20, 2020.

  1. PandA3

    PandA3 Member

    Neff S54T09X1GB
    Does anyone know where I can get hold of the control wiring diagram for this model?
    I'm having problems with it pumping out. The drain pump is not getting any power, even if float switch is raised.
    The only diagrams I can find are from a Bosch, which show the float switch directly powering the pump, but I'm pretty sure my float switch wires are from the control board.
    I've replaced the main control board (the bigger of the 2) and replaced the drain pump, and cleaned out every tube. There's power to the control board, and the display functions. The machine will start a cycle, but without the usual drain pump run first, which is weird as it starts a cycle even if the float is up.
    Any ideas where to look next? Or if I had a wiring diagram I could possibly trace the fault.
  2. kimgary

    kimgary New Member

    Will see if I can find a diagram but the pumps normally have a live to them and it is activated by switching thru the neutrals via the electronics normally faults like this are due to broken wire in the wiring harness where it comes out the bottom of the door, with time the wires harden and the constant bending with opening the door breaks them if the insulation gets damaged and it touches the chassis then because the pump already has a live it in effect gets a neutral thru the earth that’s the first place I would look
  3. PandA3

    PandA3 Member

    Thanks.. I will be looking into that tomorrow morning. The thing with this model is there are only a few wires that go up the door as the main control is in the base, and only the indicator display is at the top of the door, and the door switch. I was trying to avoid having to pull the base off, but looks like it is the only way to see and test the condition of all the wires. Luckily no football or pub tomorrow, so I guess it will keep me occupied!
  4. PandA3

    PandA3 Member

    Alas. Whole front stripped and all cables in perfect health. Tested electrically.
    Door switch is fine.
    Looks like the bottom has to come off and every cable to be checked.
    Wiring diagram would be brill if I could get one...anyone?
  5. Bob Rathbone

    Bob Rathbone Well-Known Member

    Look at the control board, you will see the output to the pump and if you trace it back into the board you will find a small triac that is used to turn the pump on and off. Bet it's blown, normally physically damaged. Replace it and you will be up and running again.
    timotay likes this.
  6. PandA3

    PandA3 Member

    I've replaced the whole PCB Bob
  7. Teki

    Teki Active Member

    I assume you have checked for voltage across the pump wire connections during a drain cycle? Have you tested the float switch?
  8. PandA3

    PandA3 Member

    You assume correctly Teki.
    Lifting float does nothing... and it always used to when I've had it apart previously to de-clog tubes.

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