Bosch Dishwasher SGS434A42GB not draining/overfilling

[derektip]

I have a Bosch SGS43A42GB which does not drain and when the cycle starts the dishwasher usually fills until the safety device cuts in then drains enough water to open the associated microswitch. The dishwasher then repeats this process, which seems to suggest that the dishwasher’s water level sensor is not working. If you can get the dishwasher past this point it runs the cycle but doesn’t drain. If you lift the safety device and hold it there the pump will then drain the dishwasher without any problem.

The dishwasher has a small float in a partially enclosed recess at the front of the filter sump, which I assume is a water level sensor (the float does float and is able to move up and down freely in the recess) but I can’t see how it works.

Any ideas?

Thanks,

derektip

[nomadPaul]

Derek , the most common problem that causes this fault is a faulty flow meter . It is a small ‘wheel’ that measures the speed of flow of water entering the machine thus telling the control module how long it should keep the inlet valve open to allow X litres of water in. When it goes wrong , the appliance gets false information on flow rates and therefore you get overfilling probs.

Part No is 424099 – impellor jug and is situated in-line with the main water inlet hose , between the rear inlet valve and the LHS water matrix. Its a small white cylindrical object.

[derektip]

Re: Bosch Dishwasher SGS434A42GB not draining/overfilling

Thanks,
I need to replace the safety float anyway so I’ll try this at the same time.

[Martin]

Re: Bosch Dishwasher SGS434A42GB not draining/overfilling

This model doesn’t use the Impellor Jug device but has a magnetic float instead. 😉

[derektip]

Re: Bosch Dishwasher SGS434A42GB not draining/overfilling

Ah so that must be the little float in the sump recess. Presumably there’s a reed switch or the like on the outside of the sump and either this has failed or there’s a problem in the controller which could be expensive 🙁

Would this explain the failure to empty as well?

PS. Thanks for the help already provided.

Derek

[nomadPaul]

Re: Bosch Dishwasher SGS434A42GB not draining/overfilling

Martin wrote:This model doesn’t use the Impellor Jug device but has a magnetic float instead. 😉

Ah , you spotted my well placed trap Martin 😳

Have got so used to the grey base DW’ with impellor jug probs that i failed to checked the parts list .

Apologies Derek

[derektip]

Re: Bosch Dishwasher SGS434A42GB not draining/overfilling

OK so I’ve checked the machine and the sensor is a reed switch which appears not to be working when I check it with a multimeter and the magnetic float. I’ll replace both the float and the sensor and see what happens.

derektip

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