"Pressostat" for Miele dishwasher

Dishwasher (Miele G638 plus) on the blink: gets to the pump-out part of the cycle and sits running the drain pump indefinitely (when I got to it this morning it was flashing the "drain/inlet" warning light). It fills and empties out, but it doesn't stop pumping when empty. I checked the obvious bits (drain hose, non-return valve etc) but nothing showed.

So now I've got the covers off and have extracted a thing that I'd expect to be a pressure switch,

has an image of something with the same part number.

My questions are:

  • is it actually just a pressure switch (on/off), or have these things got more sophisticated since I last fiddled?

  • would one expect to be able switch it by blowing into it? I've tried, and while something clearly moves inside, there's no click, and the resistance between pairs of terminals remains the same (infinite for most pin combinations, short circuit for one). This fits with my hypothesis that it's running the pump until the pressure switch says it's empty, and that never happens, but I can't see how to refute it.

  • given that it appears to have adjusting screws (one is visible in the centre of the image at the above link, the other is in the tube at the very front of the picture), can I simply fit a replacement, or will I have to adjust it up to fill to the right level? I don't have a service manual, so I don't know the procedure.

For completeness: the numbers printed in black round the plastic part are 276974 E-01/09 T.NR.5380960 1200/700 and embossed in the plastic are "Type 790", "83067", "8.8169", "?", "T85", and the terminals are numbered 12, 14, 11 and the two gaps where terminals might be are both numbered 16. I'm sure that's more info than could possibly be of use!

On-line spare parts suppliers in the UK don't seem to do that exact part, but several offer

which looks very similar, but for a more recent model, so I'll probably have to phone Miele on Monday.

Thanks,

Reply to
Jon Fairbairn
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You will probably get threatened to keep quiet! Some folks on this group will be mortified that a Miele has a fault - they always claim they are perfect.

Reply to
John

It does not have a fault. It merely requires an engineer's attention to restore it to working in accordance with the customer's expectations.

Anyway, it would work perfectly if the OP'd ran it on German water.

Owain

Reply to
Owain

Jon Fairbairn wrote on 21/03/2009 :

That is just a pressure switch.

All those I have come across click when you suck/blow down the pipe, though I suppose they might have conceivably have changed to a capacitance type. Check the pipe is clear, they do block up other than than it would be safe bet to get a replacement switch.

Reply to
Harry Bloomfield

That was what I was wondering.

I did that, and fitted it. (I didn't dare try blowing into it). Machine still sat there whirring. Misery. Booked a call-out, then suddenly thought that the pipes to the new switch would be full of air, so poured in a few mugs of water to give it something to chew on and tried again. Machine ran. Cancelled call out. Happy again.

Thanks for the advice.

Reply to
Jon Fairbairn

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