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Re: Bosch SMS3042GB/03 – no water coming in

Thought I’d just update this call in case it helps anybody else. It wasn’t a faulty inlet valve, or a timer fault, but I did solve the problem and the dishwasher has been running perfectly for a little while now.

I started taking it to pieces because I was interested in how the timer controls everything, and ended up drawing out a complete circuit diagram. Once I’d done that I realised there was no continuity in the neutral wire from the mains input at the bottom to the switch panel at the top of the door.

This puzzled me because the flat ribbon wiring from top to bottom looked in good nick, even where it bends at the hinges when the door opens. It has heavy flat sleeving on at this point so I peeled back part of this and found the neutral wire (fairly heavy gauge, coloured mauve/white) on the extreme left-hand edge had sheared clean through, even though there was no external sign of any damage. The other conductors in the ribbon were all ok, so it must be the neutral one on the edge that gets the most stress as the door opens.

I soldered a bit of replacement wire in place, insulated it well and added a bit of padding. Result : fully functioning dishwasher !

So, just a tip for anybody else with a similar problem – check all the wiring, even if it looks in perfect condition, you never know what’s lurking inside. It could be that this Bosch design is prone to fracture of this particular wire after a number of years.

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Re: Bosch SMS3042GB/03 – no water coming in

Thanks guys, both for the advice and for the concern for my safety. Actually, the only live testing I carried out was just to check the solenoid voltages, everything else was done with the mains cable disconnected from the wall. I’m no electrician but I’ve been working with electricity in some form for about 45 years, I’m currently (!) in IT technical support, which frequently involves running kit with its innards hanging out. I also completely rewired my house in the days before the H+S industry decreed we are all too stupid to be trusted not to kill ourselves, and no-one found that shocking.

So I think I’m more likely to qualify for a Darwin for the stupidity of wasting my life, spending longer trying to fix this dishwasher than it would take me to earn enough for a new one. Still, that’s curiosity I suppose, and a hatred of throwing away anything with some life left in it. It’s amazing how much satisfaction there is in spending three hours repairing an object that cost a quid and was definitely not meant to be repaired !

If the general opinion is that it’s a controller fault then I guess that’s curtains, but yes I probably will take it to pieces – that old curiosity again ! A dishwasher is one of the things I’ve never stripped down before, so it will fill a hole in my RAM. And it would be very satisfying to actually see the cause of the problem.

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Re: Bosch SMS3042GB/03 – no water coming in

Thanks for the advice. I disconnected the inlet valve solenoid and the coil resistance measured 4.2K (another solenoid nearby was 2.7K). I did some more checking with power connected – when the controller is turned to the water inlet position, one terminal of the solenoid (the one with the brown wire) is switched to 240v but the other terminal (with blue wire, in series with the float microswitches) is not switched to neutral. So this terminal is also at 240v and no current flows through the solenoid coil.

I took the door front panel off and traced the wires up to the door switch and controller. The door switch is working ok and the neutral wire to the solenoid from the controller (via the anti-flood device in the base and the microswitch on the matrix) is intact. But the contoller isn’t supplying neutral on this wire. All the rest of the wiring appears in good condition too and all the connections seem sound.

I need to do a bit more checking to see if I can find the problem, unless anyone has any suggestions ? I’m hoping it’s not a faulty controller because they list at £83 and that spells the end for this dishwasher !

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Re: Bosch SMS3042GB/03 – no water coming in

I don’t hear a click from the valve, the ticking noise I get may be the control knob creeping round. As I said, the meter shows 240v on one of the solenoid terminals, but I didn’t measure the other one, so don’t know what drop there might be. I’ll check that next, I think it goes to a terminal on the pump.

I could also test the valve with it disconnected – what sort of resistance should I expect from the solenoid coil ? Does the machine simply apply 240v AC across the solenoid when it calls for water inlet, or is there anything else apart from microswitches in the chain ?

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Re: Bosch SMS3042GB/03 – no water coming in

Thanks for the response. The supply tap is one of the inline type with a small plastic blue handle which turns through 90 degrees, turning a hollow ball inside. Is that the sort you mean ? Anyway I connected the hose to it, took the other end off the inlet valve, aimed it into a bowl and turned the tap on. There was no lack of flow !

So it looks like water is getting to the inlet valve ok, it’s just not getting any further. Any more ideas for anything I should try ?

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