Neff dishwasher not draining, pump ok no blockages??

[shandypants5]

Hello,
I have a Neff s54m45x5gb/01 Dishwasher that has started to not drain at the end of the cycle.

The first time it happened I cleaned the pump impellor out and it seemed to cure it.
But then it happened again and the pump was already clear.

I have stripped the side off the unit and I can see a blow moulded clear plastic water matrix that was pretty gunked up with sludge and lard, so I removed and washed this out.

The little float with the micro switch on that detects a flood was also pretty gunked up so I stripped and cleaned this too.

I have run the unit a few times with the side removed and it just doesn’t try to run the drain pump at the end of the cycle.

BUT… if I lift the flood float with my finger, the drain pump runs and pumps just fine so the pump itself is ok.

Any advice as to where to look or what to try next would be greatly appreciated.

Thanks.

[shandypants5]

Re: Neff dishwasher not draining, pump ok no blockages??

OK… 156 views and no replys 😕

I am not sure whether to risk buying a new control unit for it (about £80 I think) or, just cut my losses and get a new machine.

😥

[Martin]

Re: Neff dishwasher not draining, pump ok no blockages??

A new control unit would be the last thing to go for. Further investigation toward things like fill level, whether it heats OK etc would be your next move.

[shandypants5]

Re: Neff dishwasher not draining, pump ok no blockages??

Ok thanks..
But it seems to do the wash ok, and the water gets very hot. it just doesn’t pump out the dirty water at the end.

[Martin]

Re: Neff dishwasher not draining, pump ok no blockages??

Take a closer look then at the drain pump. That the Impellor is clear and not loose (shaft worn). The flap valve in the pump chamber is clear etc etc. Do please note that if the pump works fine pumping out cold water but doesn’t pump out hot water then it almost certainly is well worn and that it needs replacing.

[shandypants5]

Re: Neff dishwasher not draining, pump ok no blockages??

I have already cleaned the pump a couple of times and it all looks and feels good to me. (I am a maintenance engineer by trade, just have no dish washer experience)
I can feel a slight resistance from the motor when I turn the impellor with my finger, it sort of flicks round to the next position until I push it again, there is no slop or backlash.
Also as I said before the pump works VERY well when I lift the flood sensor float. even with hot water.
In fact this is the method I use to empty the washer after it fails so I can work on it again.

[Andy jones]

Re: Neff dishwasher not draining, pump ok no blockages??

There’s supposed to be resistance when you try to turn it. I would still suspect a faulty pump

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[Andy jones]

Re: Neff dishwasher not draining, pump ok no blockages??

Sorry I didn’t see the part where you Said it pumped whilst hot. It may well be the board but its quite unusual

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[Andy jones]

Re: Neff dishwasher not draining, pump ok no blockages??

Or as Martin said it may not be getting to the correct temperature. Does it work ok if you do a rinse cycle ? And is it throwing up any fault lights

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[Martin]

Re: Neff dishwasher not draining, pump ok no blockages??

……..also if it completes a ‘Quick Wash’ cycle without incident it will indicate the fault lies with the Turbidity sensor.

[shandypants5]

Re: Neff dishwasher not draining, pump ok no blockages??

Thanks for the help lads, it would be nice to be able to PROVE something is faulty before I spend any money on it.

It fails on all different types of wash/rinse about 80{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} of the time, sometimes it works ok. if it is still full at the end of the wash I just re start it and sometimes the second wash works fine.

There are no Fault codes or light showing.

Where and what is the “Turbibity sensor” ?

[Martin]

Re: Neff dishwasher not draining, pump ok no blockages??

shandypants5 wrote:Where and what is the “Turbibity sensor” ?

Attached to the back of the heater unit. It’s a light sensor that operates only on the ‘Auto’ cycle. So if your machine completes a programme other than auto then the Turbidity sensor is not active.

[shandypants5]

Re: Neff dishwasher not draining, pump ok no blockages??

OK thanks.
I will do a few more tests using the quick wash and then get back here.

[mikediy]

Re: Neff dishwasher not draining, pump ok no blockages??

I have the same model with the same problem. Cleaned filter, cleared pumpkin seeds from pump impeller still didn’t fix it.
Extracted it from the kitchen unit and took off side as described above (very helpful guys!) and pump runs ok. Checked exhaust pipes but no blockage.
Finally rodded drain pipe from waste end using an electrical cable draw tape (fibreglass flexible rod) and out popped loads of pumpkin seeds into a bucket with the aid of running the pump. I think they are flat enough to get through the filters. Job done! Lesson learned – all that disassembly wasn’t necessary.

[Author]

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