Bosch not cleaning in top rack (rotor is clean!)

[ericthelobster]

Have been trying to work out why our dishwasher is no longer cleaning properly (a 5-yr-old Bosch built-in; can’t find a model number – where is it?!!).

Basically, stuff on the top rack, and sometimes on the bottom one, invariably comes out with gritty residue stuck all over it. Things I’ve tried out/checked:

– Ensured spray holes in rotor arms aren’t blocked;

– Cleaned filter in bottom of machine;

– Opened door mid-cycle to check rotor arms move (but can’t tell how vigourously though)

– Changed detergent (we’re in a soft water area so no need for softener)

During the wash, water reaches the upper rotor via a flat grey conduit attached to the inside of the machine, and which mates up at the back of the upper rack with an aperture leading to the upper rotor; I’m guessing that for whatever reason not enough water is getting through? How can I tell?

One thing I’ve noticed is that after a cycle, if you lift the filter, underneath the water in the machine’s sump is really mucky; is that normal or should it be basically clean ‘rinse’ water down there?

Thanks!

[gegsy]

Re: Bosch not cleaning in top rack (rotor is clean!)

Hi
After the cycle the water in sump should be clean.
Probably you have an empty issue, or drain problem ie – where the waste of appliance feeds to. check for blockages.
If all above ok, its repairs@ unfortunately.

Greg

[ericthelobster]

Re: Bosch not cleaning in top rack (rotor is clean!)

gegsy wrote:After the cycle the water in sump should be clean.
Probably you have an empty issue, or drain problem ie – where the waste of appliance feeds to. check for blockages.

OK, thanks for that: at least it’s start! I’ve disconnected the waste hose, which connects to the sink drain via a trap like this: http://www.screwfix.com/app/sfd/cat/pro … 9&id=12794.

When I disconnected the waste hose and startes a cycle, the machine seemed to be pumping out waste water vigorously enough. The sink outlet and U-bend are clear; I just wonder, given the configuration of the waste connections below the sink, it’s likely that the junction of the waste outlet with the trap is under water? Could it be sucking that back into the machine or something? I would assume the machine would have an anti-syphon device, however?

If not; then why would I have dirty water in the sump after a wash, if the pump out is operating OK?

Thanks!

[Simon46]

Re: Bosch not cleaning in top rack (rotor is clean!)

Check it straight after a completed cycle without using the sink. The hose should go down to the spigot not up to it or the contents of your sink will end up in your dishwasher.

Regards
Simon

[ericthelobster]

Re: Bosch not cleaning in top rack (rotor is clean!)

Simon46 wrote:Check it straight after a completed cycle without using the sink. The hose should go down to the spigot not up to it or the contents of your sink will end up in your dishwasher.

OK, thanks will do: it certainly looks as if the hose has been coming up to the spigot not down, which I have now put right. But even if the hose does go down to the spigot as you indicate it should, isn’t it still likely to suffer from ingressing sink water, by siphonage?

Unless there’s a non-return valve in the machine’s output, which I’d assumed? (Isn’t there likely to be one in a decent Bosch?)

Thanks!

[Penguin45]

Re: Bosch not cleaning in top rack (rotor is clean!)

The model number is engraved in the top edge of the inner door panel. Without it, we will struggle to give specific advice relevant to your appliance.

Regards,
Penguin45.

[ericthelobster]

Re: Bosch not cleaning in top rack (rotor is clean!)

Penguin45 wrote:The model number is engraved in the top edge of the inner door panel. Without it, we will struggle to give specific advice relevant to your appliance.

Ah, found it! It was covered in a coffee stain or something. It’s SGV4313GV/17.

Machine does seems OK now, having done one full wash since re-routing the waste pipe yesterday; however I’m still concerned about the potential siphoning issue mentioned in my last posting?

Thanks

[Simon46]

Re: Bosch not cleaning in top rack (rotor is clean!)

Water cannot flow uphill. 🙂

Simon.

[Penguin45]

Re: Bosch not cleaning in top rack (rotor is clean!)

Simon, this machine cannot syphon due to the air break in the fill/drain matrix.

The problem will be either that the machine is underfilling – usually caused by a partial blockage of the transfer hose in the front left corner of the chassis – or that the circulation pump is failing in some way. I had one last week running on the start winding only, giving exactly the same symptons.

Either way, it’s a bit of a demolition job to sort out, so pro help may be your best option. Check repairs@ or Directories for a UKW repairer in your area.

Power off if you’re going inside.

Regards,
Penguin45.

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