Bosch SGS43E08GB/43 Dishwasher Problem

[jontymox]

Good evening all,

Wondering if anyone can advise on a problem with the above m/c?

Essentially, the m/c is constantly in drain/safety mode when any programme is selelcted.

The time remaining display does count down, but typically remains on 1 minute forever, and the customer reports has stuck on various times prior to my visit.

Upon initially testing the m/c’s operation, water entered correctly, and carried out a wash sequence, before soon going into constant drain mode.

The water heated up, so probably not heater related.

The customer did say Bosch fitted a new display module recently,(under a safety recall) and I wonder if this is relevant?

Any help much appreciated.

jontymox

[Martin]

Bosch SGS43E08GB/43 Dishwasher Problem

jontymox wrote:The customer did say Bosch fitted a new display module recently,(under a safety recall) and I wonder if this is relevant?

I would imagine only if the problem were there immediately it was replaced?

Have you checked the anti-flood device?

[jontymox]

Re: Bosch SGS43E08GB/43 Dishwasher Problem

Good morning Martin,

The anti-flood device appears fine, with both micro switches giving .3 Ohm readings when manually operated.

Are further tests of this system required/possible?

Thank you,

Jon

[Martin]

Bosch SGS43E08GB/43 Dishwasher Problem

Yep, inspect for surface component damage on PCB. I wouldn’t mind betting a triac has blown its head off?

[jontymox]

Re: Bosch SGS43E08GB/43 Dishwasher Problem

Hello again Martin,

Visually inspected PCB yesterday, as I suspected it.

However, it looks fine… is there any way of testing it, or is that a specialist job?

Kind regards,

Jon

[Martin]

Bosch SGS43E08GB/43 Dishwasher Problem

No it can’t be tested I’ m afraid. You didn’t answer my earlier question about it whether or not the fault was apparent SINCE the BSH agents replaced it?

[jontymox]

Re: Bosch SGS43E08GB/43 Dishwasher Problem

Customer has confirmed problem only began recently… control module renewed around one year ago by Bosch under warranty.

Jon

[Martin]

Bosch SGS43E08GB/43 Dishwasher Problem

OK probably best to disregard any PCB probs then. Just the usual suspects like float in pressure chamber (crudded up)? Water diverter sticking? Circulating pump impeller crudded up? Turbidity sensor crudded? Does the fault only occur on ‘auto’ cycles and works OK on normal non-auto cycles?….stuff like that! 😉

[jontymox]

Re: Bosch SGS43E08GB/43 Dishwasher Problem

Thanks Martin,

Carrying out further investigation/tests.

Jon

[jontymox]

Re: Bosch SGS43E08GB/43 Dishwasher Problem

Evening all,

Have now cleaned air break/matrix, pressure chamber/valve and inlet valve.

Machine will now fill, but upon reaching correct level, immediately drains for a few seconds, before filling for a few more seconds, then draining for a few seconds… etc

Have you come across this unusual sequence, which occurs on all programmes?

Jon

[Martin]

Bosch SGS43E08GB/43 Dishwasher Problem

jontymox wrote:Machine will now fill, but upon reaching correct level,

Not sure what you are referring to here by “correct level” because the pressure switch is the first micro switch that fires up the circulating pump. It then continues to fill whilst water is displaced in the tub by the pumps action. The PCB calculates the period the inlet valve continues to fill (usually another 30 secs or so but short enough to ensure the safety level isn’t reached.

Only then at the point when the inlet valve stops is the “correct level” reached. If you stop the machine and check inside the water should have reached the bottom threads of the salt container ( rough guide).

So, my question for you is: Does the pressure switch operate the micro-switch as it fills?

[jontymox]

Re: Bosch SGS43E08GB/43 Dishwasher Problem

Thanks Martin,

From memory, no, pressure switch not operating micro switch as m/c fills. Will confirm when I have opportunity.

On reflection, the m/c is taking 2-3 minutes to fill, and the circulating does not operate at all.

Will check pump continuity, although it spins freely.

Inlet valve gives a good Ohms reading, although now suspect.

Jon

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