Miele G640 dishwasher problem - inlet/outlet flashing

[JimSti]

I have done everything advised in the manual re cleaning the filter and the area around the non-return valve and drain pump. The machine is about 10 years old, and used every day.

If I use the pre-wash cycle, it drains, fills to the correct level (>4mm above the coarse filter) the circulation pump starts working and washing for about 10 seconds and then it stops, with the red light flashing, and water at the bottom .

I have taken off the bottom panel and there are no leaks. I have also checked the inlet and outlet hose for obstructions and there are none.

I have removed the circulation pump and checked for whether it might be seized or stuck. It rotates, though quite stiffly. I found a post on another forum that recommended spraying WD40 on it at various points where there are moving parts, so I have done that, though it didn't seem to rotate that much more easily after doing so.

I also had a look at the heater level switch and saw that it seemed to be a bit scaled up inside with light brown deposit (we are in a hard water area), so I put a bit of descaler in it and then after leaving it for a bit rinsed it out.

I though I had fixed it because I was then able to run a prewash programme and then a normal programme without dishes in, but the first time I have run it with dishes the problem has come back again.

Can anyone suggest what the problem might be? Any help would be very much appreciated.

 

[francis2]

check the pressure switch is actually switching, it could be theres not enough pressure building all the time the pumps running to keep it closed have you actually had the pump to bits to check the impellor for fluff/debris/ hard fat etc Id be surprised if there wasnt some muck in there after 10 years as thatll reduce the pumps efficiency easy to dismantle just be careful with the shaft seal

you can actually back the tension off on the nylon crosshead screw in the centre of the back of the switch that way if the pumps a bit worn the cycle will still run

 

[JimSti]

Thanks very much.

It turned out to be the heater level switch causing the problem. I replaced it and all is now working fine again.