Bosch dishwasher SGS09L08 not draining

[martyn_123]

Hi,

I have a 3 year old Bosch SGS09L08 LogiXX dishwasher which has recently not been draining fully – water remains above top filter although washing cycle has completed and dishes etc are washed OK. I have read other threads on this site and have fully checked the pump impeller for obstructions and also that the outlet pipe is not obstructed/kinked. Mention is made in other threads of a non-return valve which could possibly be a problem but am unable to locate this on my model.

Any ideas, or is it a case of replacing the pump?

Martyn

[nomadPaul]

Re: Bosch dishwasher SGS09L08 not draining

Is the drain hose connected to a sink drainage system or a stand-pipe ? If its connected to the sink , does the drain hose loop upwards prior to the connection ? It could be siphoning back in from the drain end so its important to have an ‘air gap’ , created by a raised loop to prevent this.

[martyn_123]

Re: Bosch dishwasher SGS09L08 not draining

yes, it is connected to the sink with an inverse “U” prior to the connection. It is odd because the excess water can be drained away using the “drain” option (sometimes takes a couple of attempts) which appears if a programme is started and then immediately interrupted by opening the door.

The arrangement for the outlet hose is the same as I have used for the last 15 years. The previous dishwasher was also a Bosch and was still going OK after 12 years when we decided it could be getting to the end of its life.

Martyn

[Trilobite]

Re: Bosch dishwasher SGS09L08 not draining

I have this machine and no major problems so far.

The drain pump does work in surges, it is a bit disconcerting!

When totally drained:

Power OFF, remove filters. Use absorbent sponge/cloth to mop up the excess water that always remains in the sump.

A small cover may be seen 2- 3 inches, secured by a single Torx screw; remove it. Cover lifts off, revealing the drain impeller. Check to make sure that NOTHING is caught in this area (seeds, broken glass, labels, wire ties, etc).

Looking toward the rear of the impeller, you should be able to see a black rubber flap that slots down into place; this lifts out (a blunt, small flat screwdriver, or similar object may assist).

Rinse under running water and replace.

Clean the filters under hot running water.

There is also a transfer tube in the sump wall, at the 6 O’clock position. It leads off left, curving backwards and upwards. This feeds tap water down into the sump (ie a fill tube). It can accumulate grease and food soils. A narrow bottle-brush and a VERY GENTLE rodding action will remove most deposits.

Replace all parts in reverse order.

Purchase Dishwasher Cleaner (FINISH £2-£3, or ALDI’s own brand £2 for a twin pack! They appear to come from the same factory).

Remove the sticky peel-label on the lid to reveal the wax seal, place upside-down in cutlery basket (it DOES fit, though rather snugly; inserting it a centimetre or two into the cutlery basket is enough).

Run the machine on “AUTO SUPER WASH”; this will allow the machine to use the maximum temperature and intensive action. Wax seal dissolves at high wash temperature. (It will not be affected by the warm heated prerinse on this cycle).

When cycle is complete, discard the empty bottle.

You may have to repeat this cleaning cycle in order to clean the drain matrix, which forms part of the fill matrix/heat exchanger assembly on the left-hand side of the machine. This drain matrix has been known to clog with deposits.

I tend to use the AUTO SUPER WASH cycle for virtually all loads, as I’m not convinced grease is properly flushed away at lower temperatures.

[martyn_123]

Re: Bosch dishwasher SGS09L08 not draining

Hi Trilobite,

Many thanks for this detailed reply.

I have already (several times) had the cover off the drain impellar to check there is nothing caught in this area. What I am unable to see is this “black rubber flap”, my machine does not seem to have this feature. By the way have found that a basting siphon is ideal for removing the small amount of excess water left in the impellar sump.

When you mention the sump wall, do you mean in the same area as the impellar. Sorry if this question seems a bit daft but am unable to see this transfer tube in the impellar sump area.

Have been using the dishwasher cleaner (Finish one) for several months now (on the Auto Super Wash) so this should have kept the machine clear to some degree.

Thanks again for the response.

Martyn

[martyn_123]

Re: Bosch dishwasher SGS09L08 not draining

Hi again,

Have just had a further look at the sump and now see the black rubber flap you mention (thought the top of this was a seating seal for the impeller cover!).

Will have a go at cleaning the transfer tube after purchasing an appropriate bottle cleaner although is does feel (as far as my finger will go) fairly clean.

Did a Quick Wash and water mostly drained OK although it has done this before and left water the next time it is used. Will see how it goes.

Once again, many thanks for the advice.

Martyn

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