Bosch SGS5302GB/07 Dishwasher

[FlyingBrick]

Have a Bosch SGS5302 dishwasher that stays stuck in a wash cycle with no heating on?
Main pump,drain pump, heater reads 23 ohms with pressure micro switch working ok. All the microswitches on the LHS panel checked and the plastic water holder cleaned out as the red float inside at the top was found stuck.
If the Intensive and Eco buttons are pressed together the numerical display shows “0” but keeps running in a wash cycle staying cold.

If power turned back on wash cycle bar comes back up and it just stays in that cycle with no heating coming on but pumping the water around.
Is this a pcb control panel error or may be a NTC sensor?
Is there any way to re-set the microprocessor board pcb to check it has not screwed up.

Running out of ideas as Bosch is not my main repair business.

Chris

[WhiteVanMan1]

Re: Bosch SGS5302GB/07 Dishwasher

Have you checked the heater relay for a dry joint? Notorious on these machines.

[mikehha]

Re: Bosch SGS5302GB/07 Dishwasher

check the board chris as they are prone to dry joints around the heater relay

[FlyingBrick]

Re: Bosch SGS5302GB/07 Dishwasher

Thanks for such a quick reply.

Assume the heater relay is soldered onto the main pcb in the door at the top as I have noticed also that the quick wash button no longer hits the control board membrane? The plastic detent has brocken off leaving the quick wash cycle redundant as nothing is pushing onto the microswitch membrane.
Thought at first it was jammed in causing the microprocesser to lock up.

Chris

[WhiteVanMan1]

Re: Bosch SGS5302GB/07 Dishwasher

Yes the relay is on the PCB, and easily repairable

[FlyingBrick]

Re: Bosch SGS5302GB/07 Dishwasher

Thanks WhiteVanMan1 and Mikehhah

Spot on , yes the track on the relay was burnt out and going nowhere.
Re-soldered a new copper track back on and hey presto the heater came straight on and thought job done thanks to you both.

Just about to put the panels back on the sides and noticed that when the Quick wash is used for a test run the temp went up to 68 degrees centigrade and after around 35 minutes the “0” numerical display came on but the main pump was still running and the heater was still on ?

Turned the mains switch off and re-set control panel and have now put in Eco wash which ran up to 70 degrees centigrade before the heater power came off and is still running through its cycle.
Will have to wait for 80 mins plus to find out if it will drain and turn off by itself.
Have a fluke attached to the heating element to see if it comes back on again when the temp drops.

Any views on this one!

Chris

[FlyingBrick]

Re: Bosch SGS5302GB/07 Dishwasher

Back again WhiteVanMan1 and Mikehhah

Bosch dishwasher will cut out the power on & off for the element and keep the temp constant on a Eco wash but comes up with “0” after the aprox wash time but just keeps going with the water hot and the main pump running the wash cycle until the power switch is turned off.

Water level looks high with around 3 cm around the edge and starts to slosh a little out at the front while in the wash cycle. It will not turn off and go into the drying cycle.
Any ideas on this one.

When the element relay burnt the track right off would this have screwed up the chip on the control timer pcb?

Have I got to go down the pricey new pcb route to fix this dishwasher?

Chris

[WhiteVanMan1]

Re: Bosch SGS5302GB/07 Dishwasher

If you have cleaned out the level switch chamber, and the sump hose. and the heater circuit is working ok, then it sounds as if you have done all you can. It sounds as though the module is the next step, though my concern is why the module has blown in the first place. Having said that, I have known them to go just through overheating due to the dry joint. These machines are quite straight forward as a rule, but it’s that sinking feeling that the module turns out to be not the problem after all, and there is some intermittent fault that emerges once the new module is fitted. I am only painting the worst scenario here, my gut feeling is that a new module will fix it. Sorry, it’s the best I can do. Good luck. Steve 😀

[FlyingBrick]

Re: Bosch SGS5302GB/07 Dishwasher

Thanks Steve
Will have one more hard look at the switches and hoses before I pull my hair out and deliver it back.
As you point out I do not want to buy a new control module at nearly £100 only to find out that it is something else.

One more go tomorrow before I inform the customer of the bad news.

Chris

[FlyingBrick]

Re: Bosch SGS5302GB/07 Dishwasher

Back again after checking all the parts on the dishwasher.
Having closely inspected the main pcb after soldering the burnt heater relay tracks found another dry joint close to the relay.

Cracked solder joint to an ic on the board having looked underneath a 8 times mag lens.
All put back together and now dishwasher heats up and finishes it’s cycle.

Thanks chaps yet again and saved the customer some £104 for a new board. So happy they put on an extra £20 note.

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