Miele W842 – drain pump keeps stopping, but no blockage

[marklensman]

The drain pump runs for a few seconds, although it sounds like it’s struggling, then it stops and the “Rinse” light flashes.

There’s no obstruction in the pump that I can see when I remove the filter, and the problem occurs even if I run a rinse cycle with no water in the machine and the filter left off.

[electrofix]

Re: Miele W842 – drain pump keeps stopping, but no blockage

it sound like the machine thinks there is still water in it possibly

there is a small rubber tube that connects to the panel to detect water height

find this tube and as a test disconnect it from the panel, set a rinse programme and see if it starts to fill. If yes switch off, drain and follow tube to the bottom of the machine where it will be blocked in the pressure chamber it connects to

if you do blow in the tube to make sure its clear do not blow through it while its connected to the panel as it damages the sensor

Dave

[1totalshambles]

Re: Miele W842 – drain pump keeps stopping, but no blockage

One thought! These things are fitted with a magnetic Askoll style of pump. Could simply be the pump bearing has worn out. If so the impellor would have a distinct amount of side play. Some Bosch pumps on older models fail the same way.

[marklensman]

Re: Miele W842 – drain pump keeps stopping, but no blockage

Thanks guys. I’ll check these.

[marklensman]

Re: Miele W842 – drain pump keeps stopping, but no blockage

EDITED.
OK, I removed the pump. Miele 5012770 (DPS 25-041, 30W, Hanning EW)
https://www.dropbox.com/s/vxa2bgcrfkhu1zq/Miele{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d}20pump.jpg?dl=0

There is a very slight rattle if I run the pump free from its housing. It still stops after 15s or so, and the warning flashes.The warning flashes after 15s into a drain cycle even with the pump totally disconnected, so it’s not some mechanism that detects excessive pump current.

BTW, there was no cotton thread etc wrapped around the rotor. I did find some tiny metal parts in the housing that had escaped my attention when I cleaned the filter – (a dressmaker pin and two small spectacle screws) – these perhaps account for the erratic “struggling” before.

@1totalshambles
There’s no side play at all on the rotor. When rotating the impeller, apart from the expected cogging from the magnet, there is a smooth frictional drag as if there is a silicone rubber seal on the rotor. Is this normal?

@electrofix
I disconnected the tube from the panel – I could blow through it OK from the freed panel end.

On reflection, I’m puzzled that the machine would switch off the pump if it thought there is water still in it.

I’d expect it would switch off if it thought there was NO water in it, but I can’t understand why it would flash a warning light in that case.

I haven’t tried filling the machine, as I know it won’t drain.

[marklensman]

Re: Miele W842 – drain pump keeps stopping, but no blockage

Now fixed.
Having found the small parts inside when dismantling the pump I thought I’d reassemble everything and see if the pump ran better. The “Rinse” light started flashing almost immediately, earlier in the cycle than I recalled (although I can’t be certain). Pretty confident that the pump was now OK I searched the forum for “Miele rinse light flashing”.

I found incognito’s post that illustrated a likely cause of the problem miele-w844-won-spin-flashing-rinses-light-resolved-t34677.html#p189087

and springchicken’s post which detailed where to get the electronic components for the fix miele-w844-won-spin-flashing-rinses-light-resolved-t34677-15.html#p417863

I’m very experienced with PCB repairs, and managed with desoldering braid rather than using a desoldering station. It IS tricky working on through-plated PCBs, especially when component leads have been bent over as here, so I suggest using one of the services listed in the above thread. I used this desolder braid: https://uk.rs-online.com/web/p/desolder … ds/2214021

Very many thanks to all who contributed to this and the other thread.

[electrofix]

Re: Miele W842 – drain pump keeps stopping, but no blockage

I would also check the shock absorbers as worn shocks will cause excessive movement which can jar the relay contact and cause the fuse to blow

Dave

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