Smeg dishwasher dwd1sse1

Here we go again. The above dishwasher (serial no. 0407256 183) is allowing you to turn the time delay knob one click to the right (on position), select any programme, but when you press the start button it gives a 1 second blast of drain pump then reverts to the programme you have selected (as if the programme has been cancelled immediately). There’s no water in the base and no signs of any prior leakage. If I disconnect the drain pump, float switch or NTC I get either a”–” or “E4” on the display. Disconnecting the heater makes no difference. I have managed to get the appliance to run a couple of times (fill, circulate, heat, drain) but if you open the door and interrupt the cycle it goes back to the fault condition. I’ve stripped out all the door wiring from it’s protective sheath but there’s no signs of any wires having broken or suffered from work wear.

I therefore replaced the main module – worked once but when I opened the door and closed it again the fault came back. Should I just go whole hog and change the start/display board along with the time delay and prog select swithes. After 6 hours on the job my brain’s addling! 😕 Any experience gratefully accepted.

Cheers Ian