Bosch Dishwasher question

[pauljtomlinson]

Hi I have a Bosch dishwasher SGV43A03GB which is about 4 years old. It has worked very well until recently - the wash quality is now very hit and miss, sometimes getting everything spotless, other times leaving deposits especially on the top rack. I've tried using dishwasher cleaner and have disassembled the spray bars and checked there is no blockage or scale, manually cleaned out any grease build ups etc but still can't work out what's wrong. The one thing I noticed is if I put it on the prewash cycle and pull the door open whilst it's wasing, the bottom rotor is spinning but the top one isnt although water is coming out of the rotor bar. It is free to move and as previously mentioned has been cleaned and I am sure there are no blockages. I have removed the grey plastic trunking between the bottom of the dishwasher to the top and it is definitely not blocked. Once the trunking is removed it is evident that the bottom and top rotors are fed from different channels. Does this indicate a problem or is it that the program selects the top rotor at different times to the bottom rotor or should they always operate simultaneously ? If it indicates a blocked pump is this possible to look at in-situ ? This model is built in so is a fair amount of work to remove from the worktop. Any advice or tips welcome !!

[John]

First - are you sure you haven't set it on a programme to only wash the bottom level?

Is the top drawer properly opening up something at the back which admits water to the top arm?

(I have a Candy / Hoover so I can't comment on exact details)

[Bob Eager]

You haven't mentioned the sump filters (there are two in ours). They are accessed (in ours) by rotating the thing over the drain hold (in the bottom on the washing compartment) anticlockwise and lifting the base plate out. One is attached to the plate, one is a loose gauze cylinder.

If these are blocked there may not be enough water getting through to feed both rotors adequately.

[pauljtomlinson]

The sump filters are both clean - I rinse these out every couple of cycles.

[Bob Eager]

Just in case the rotor thing is a red herring (although I'd check the water feed from the back of the basket to the centre of the rotor)....

Salt. Is there a salt feed problem; it can give these symptoms. Is the salt OK, and has the salt selection lever been moved accidentally?

[Bob Mannix]

Are there lemon or orange pips in the rotor arms. These often block the end jets which provide most of the motive power to circulate the spray arms but fall back into the arms when there is no flow. This happened quite a lot with my Bosch. Take the arms out and see if they rattle?

[pauljtomlinson]

are both clean - I rinse these out every couple of

No, I am sure they are completely clear.

My gut feeling is that the pump is blocked and insufficient water is being pumped up to the rotor - hence my question about what is involved in accessing the pump.

[Bob Mannix]

Fair enough - does sound like a blockage somewhere then. Some things were accessible from the front on mine but for a full pump investigation I think we are talking remove machine and strip down. On mine there was a sort of finned exit hole from the sump, below the filters. I often had to clear these channels out with a pointy implement, dragging the stuff out into the base of the sump and fishing out by hand. You could even try drain unblocker but no liability accepted etc!!!

[Lobster]

Blimey, what the hell is it with Bosch dishwashers this week ?!!

Ours showed symptoms very much like this a couple of years back, and I couldn't get to the bottom of it at all. In the end we got an engineer out, and he quickly found the problem was due to totally clogged up pipes inside the machine - it looked totally disgusting, bit like those photos you sometimes see of smoker's arteries. He cleaned it all out, and it worked fine thereafter. I think it was the pipe at the bottom, leading to/from the pump which he removed.

Presumably the part-blockage in the pipe prevents adequate water getting to the upper rack, and what does get through is likely to be contaminated by the pipe contents.

The bloke said that every so often we ought to use one of those 'dishwasher freshener' products (where you run the machine empty on a hot cycle with this power-detergent stuff) - we've never done so as we regarded them as a marketing con. Anyway, FWIW we use them now, and the machine's been fine since (but then again, it took 4 years for the problem to become apparent in the first place, so who knows!)

David

[Alan J. Wylie]

Is there a blocked filter at the far end of the cold water inlet pipe? The filter may be found inside when you unscrew the 3/4" BSP coupling.

Do you have a self cutting fitting? When my maching had similar problems both the filter and the fitting were badly clogged up.

[pauljtomlinson]

OK - looks like a stripdown tonight !!

I guess I'll have to remove the whole thing out of the kitchen units - is the pipe work then accessible or do I need to take covers of the dishwasher ?

Are there any service manuals or drawings available online ?

Thanks so far for everyone's help.

[John]

Is the spraybar a part of the top rack? If so, have you investigated how it gets its water supply when pushed in? (or is it a fixed spraybar?) Reason for asking, is mine has a plunger that opens a valve at the back. If this was broken then the symptoms would be as you describe.

[Lobster]

Good luck - it's a pig of a job. All the parts are incredibly inaccessible I'm afraid.

The only drawings I've coe across are at the Boasch spares site at:

"quickfinder") but they aren't a lot of help for dismantling etc.

David

[Pete C]

Hi,

I'd try a few washes on the hottest setting.

cheers, Pete.

[pauljtomlinson]

Well I spent a couple of hours last night and think I'm making progress.

Once the dishwasher was out of the kitchen units (it's built in integrated dishwasher) I took the left hand side cover off and a metal cover at the bottom front off, both held on by 2 screws (torx)

It was immediately obvious that the pipe running at the bottom between the sump and the large plastic 'slab' at the side was gunged up. The pipe just pulls off and after rinsing out thoroughly (the amount of sludge removed was unbelievable) it cleaned up fine. I also remove the plastic thing at the side with various valves and switches attached, this too was very sludged up.

I ran the dishwasher up with the covers still removed and I could see water circulating OK, also the noise of the water sloshing around the inside was much more evident than usual so I think it hadn't been working that well for ages (which ties in with the the gradual deterioration in wash performance)

To start with the top rotor still didn't spin but later in the cycle it was, so possibly this is by design, or maybe with the majority of the sludge removed, the last few bits are being shifted and the remaining contamination will clear. I'm going to run it tonight with some proper dishwasher cleaner to hopefully clear the last of the sludge and hopefullt that'll be it.

The lesson to learn I think is to use cleaner regularly. Despite my machine looking immaculate on the inside yet totally clogged inside was a real eye opener.

I'll report back when I've done the final clean !

Thanks to everyone for their suggestions

[pauljtomlinson]

Have now done about 4 wash cycles and the performance is perfect !!

I think the thing to check for is the state of the water in the sump after a wash, previously, with the filter out, it was about half full of murky water, now, it is almost empty with the water at the bottom clean. I think that alone is a pretty good indication of whether the pipes are blocked.

Clearly the dishwasher hasn't been working at its best for some time - although a fiddly job didn't actually cost anything other than a bottle of dishwasher cleaner I used after I'd stripped it down.

[steve.button]

Hi,

I'm getting exactly the same problem, but I cannot get the sides off. I've removed the two torx screws from the left hand panel but it seems to be stuck at the back of the machine and will not come off. I don't want to bend the panels, but I've been wriggling the blasted thing for about 15 minutes and it won't budge.

Any suggestions?

I really don't want to call out the bloke to fix it again and spend =A350 for him to remove the side panel and clean out some peas from the pipes (for the THIRD time)

The really annoying thing is we try to rinse everything a bit before we put it in, but some stuff seems to still get missed. Almost not worth having a dishwasher if you have to clean everything before you put it in!!

Thanks all!

Steve

[Pete C]

If the plates are stacked before rinsing, sometimes peas and orange pips can hide on the *bottom* of a plate.

cheers, Pete.

[Lobster]

There are no other fixings per se. ISTR there were two circular indents in the back face of the panel - ie, on the 1" 'lip' which bends round the corner to the back of the machine - at the top and bottom. There's a small hole at the bottom of each indent which accepts a tiny circular plastic lug on the back of the machine, holding the panel in place, so ISTR having unscrewed your two torx screws, you need to be splaying the panel out sideways a bit, then push it backwards to disengage the lugs.

Mine's still leaking; haven't quite plucked up the courage to start dismantling the gubbins yet...

David