Bosch SGS42 not starting

[wordingh]

Hi,

I hope someone can help me.

My dishwasher does not want to start a cycle. I have tried all programs, and the button lights up, and the unit starts to “hum”, but no sign of the unit filling with water and arms spinning. I have checked that I have water into the machine, waste hose is unblocked. I have also cleaned out the pressure chamber and inlet pipe to it, as that was very gunky. But still no luck 🙁 The unit does not seem to be leaking, and the overflow sensor seems to work as expected, i.e. pumps starts up.

There is a faint burning smell around the machine, but I have not as yet located what it could be..

Does anyone have any ideas what could be wrong ?

Thanks,

Paul..

[Penguin45]

Re: Bosch SGS42 not starting

The first action of any programme should be to run the drain pump. This will be followed by fill – when water level is attained, the circulation pump should kick in. On a main wash sequence, the dispenser will fire and the water should be heated.

If none of the above is happening, I’d be looking at the door switch mechanism; and if that is working, possibly the PCB.

Full model number would be useful, please.

Power off if you’re dealing with this yourself.

Penguin45

[wordingh]

Re: Bosch SGS42 not starting

Hi Penguin45,

To be honest I cannot find a single sticker or marking which states the machine model on the dishwasher. I am pretty sure it is a SGS43C02, it’s a Classix 600mm, with 4 buttons to control the programs.

It makes a few “clicks” when I first power the machine on, but then just sits there with a quiet humming sound, and nothing further happens. Could the circulation pump have failed ? if so, can I do some basic checks of it ? (power off obviously 😉 )

Br

Paul…

[wordingh]

Re: Bosch SGS42 not starting

as a follow up to this, when I switch the machine on, no water seems to rise up the clear plastic water matrix on the lefthand side of the machine. (fed by the blue pipe. Maybe an inlet valve has failed and is not opening ?

Paul…

[clivejameson]

Re: Bosch SGS42 not starting

The model number is laser etched onto the top edge of the door and is sometimes only readable in the right light.

It’s not unknown for the element to fail and take the pcb with it, check the continuity and earth leakage of the element first then the opration of the pcb as Penguin has described 😉

[wordingh]

Re: Bosch SGS42 not starting

Its a SGS43C02GB/35

[wordingh]

Re: Bosch SGS42 not starting

Hi,

It is now letting water in, but does not seem to know when to stop ! Thus it fills up, until the red float valve kicks the waste pump in, empties, and then starts filling up again. Is there some meter which detects the water level, and thus switchs the inlet valve off ?

Thanks in advance,

Paul…

[clivejameson]

Re: Bosch SGS42 not starting

You say the pressure chamber was well gunked up, i suspect you haven’t got rid of it all particularly in the small chamber underneath the diaphragm switch or under the black baffle within the chamber.

Failing that, check that the diaphragm switch operates when the machine fills…the pcb detects this then times a top-up 😉

[wordingh]

Re: Bosch SGS42 not starting

Hi Clive,

I suspect it could be the “yellow” diaphram switch, if I manually pull the blue lever attached to the switch, then the dishwasher seems to spring into life, and start rotating the arms etc. I have taken the pressure chamber to pieces again, and cleaned it, but the diaphram switch does not seem to operate, before the anti-flood “red” float kicks the waste pump in, and empties the machine. Do the diaphrams stick or something ? It does not seem to operate the microswitch sucessfully.

Br

Paul…

[clivejameson]

Re: Bosch SGS42 not starting

In all that i’ve seen i’ve had two stick, both of those were because the machine had been stored without use for several months and after they’d been manually operated were fine.

If the water is rising up into the small chamber under the diaphragm but the diaphragm doesn’t operate the lever then there must be an airleak. You can check this by physically blowing into the small chamber 😉

Remember, power off at all times :zap:

[wordingh]

Re: Bosch SGS42 not starting

Hi Clive,

I gave the diaphram another clean-out, and moved it around a bit, as it seemed to be getting stuck. I did a test wash last night, and the diaphram worked as expected, and the wash completed sucessfully. I will do another few washes over the next few days, before I put the top & sides back on.

Thanks to all, for your advice,

Paul..

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