I haven't seen this one, and I just went through it, so as my feeble
contribution to the knowledge-base we call the Internet, here's a
Last night, my son came to me complaining that his water tasted funny.
That's how most things start around here. What he meant was that he
could still taste the apple-juice in his sippy-cup. Being the good
Dad that I am, I took apart his cup, smelled the juice, and got him a
Our dishwasher (4 year old Bosch 3300/SHU) was running, so I opened
the door, waited for the dripping noises to stop (I know, you're
supposed to push the on/off button first, but I hand't read the manual
at that point :) chucked his apple-juice tainted cup in, and started
it again. The machine burped, then went into its drain cycle. Drat,
I thought, must have been at the end of the wash. 10 minutes later it
was still making draining noises, but not actually exhausting any
water because, well, there was none left.
At this point even my wife noticed that things weren't completely
right in the kitchen. Accusing looks were traded amongst all parties
(except my son who was happy with his new water cup). So I switched
it off at the on/off switch, and said something like "I think I broke
the Dishwasher". Not a smart thing to say it turns out, since money
has been rather tight since I've been out of work for over a year.
However, I'm a handy sort, and I figured that it might be possible to
diagnose and fix it myself. This is 8 at night BTW. So, the first
thing I did was go dig out the users guide. Not much help there, this
was not a failure mode that they hadn't forseen. One more time for
good measure in case it magically fixed itself, switch on, hear the
pump, press all the buttons at least twice, no change. Off again. On
again. Off Again. Unplug. Plug in. On again. No change. Still
furiously pumping air. Sigh.
So I started with the cleanout procedure. Hmm. Didn't know you're
supposed to do this every month. Lets see, 48months old, 1 cleaning
about to occur, well better late than never eh? Unscrewed the plastic
bit with the 'microfilter', slid out the metal filter. It's all
covered in some white sludgy material. Some of it has gone rock hard.
Well I guess we do need to clean more often. Picked out all the ex
bits of food which haven't dissolved in 4 years of nightly exposure to
almost boiling water (the end-bits to Avocado Pears mainly) and some
more of those rock hard white things (have you been stuffing teeth
down this thing?)
Put some water in, try again, drains the water, doesn't stop. Ah
look, there's a torx screw that looks like I might be able to get off
without destroying the machine. Maybe something under that plastic
cover it's holding on is responsible for the problem. Out comes the
screw, off comes the cover with a bit of rocking and tugging, and more
of that nasty white stuff. Some of which looks quite 'fresh', namely
that when you crunch it with your thumbnail, it has crystalline power
White crystalline powder? Hmm. Under the cover is what appears to be
a little impeller, probably the drain-out pump. Nothing obvious here.
Put it all back. By now I'm becoming convinced that there must be
some limit switch in the machine that senses water level in the sump,
and that somehow that has got stuck. Where would a schematic be.
Inside the machine? Probably. Pull off the base-plate, pull out the
machine, look around, everything looks good, ah, there's a folded up
piece of paper that says "Wiring Diagram". Lets take a look.
Yep, it's a wiring diagram. Shows all the bits, but not where they
actually are. Completely useless for this task. Well at least I
know there's nothing useful I can do under here, so I put it all back
Next, (should have done this first I guess), onto the Internet. No
direct hits on this particular problem -- which is why I'm documenting
it here --, but lots of advice including how to rig the door-switch so
you can watch the machine working while the door is open. A piece of
my advice here: don't do this with any substantial amount of water in
the sump unless you plan to wash the entire kitchen afterwards, or you
can slam the door closed very very quickly :) And wear safety
glasses: I always do and last night it paid off when the machine shot
a blast of water vertically into the roof of the chamber, and
everywhere else including my head.
The one thing I did pick up on was that you should periodically
consider doing a Citric Acid crystals cleaning of your machine if you
are in a hard water area. Well, our water is so hard the ducks walk
on it. But I didn't have any Citric Acid crystals to hand, being
about midnight at this stage I didn't think I was going to go out and
get any. But, I did have a bottle of CLR: (Calcium Lime Remover?),
and it works great at getting rid of limescale buildup. What the
heck, I thought, last chance, chucked quarter of a bottle in the sump,
started the machine, and I swear it immediately switched from drain to
AAARRGGH! I broke it for good now I thought. Quick, open the door
and chuck a bucketfull of water in. Heart pounding, my wife will kill
me when she finds out I really broke the machine. On again, machine
pumps, then stops like it should. Huh? It's working again.
Then it struck me what the white gunk was. Dishwasher powder. When
we started the cycle earlier in the day, the little door that hold
back the powder had flipped open when my wife closed the door, and it
had emptied all onto the floor of the machine. She asked me "will
this be ok" and I said "sure". Nope.
What appears to have happened is this. The powder sat around at the
bottom of the machine, forming under moisture and heat, a rock
hard/sludgy substance that sank into the sump of the machine when I
stopped the cycle. This then appears to have gummed up the float
switch (I still don't know where this is, but it's on the wiring
diagram, and presumably somewhere in that sump), causing the
dishwasher to keep pumping because it thought the sump was full. The
introduction of CLR is like hot-knife-through-butter to dishwasher
powder, a fact I verified by mixing the two on a dish and seeing lots
of vigorous foaming.
Once I throw the CLR in, it dissolved whatever was holding the float
switch in the "float" position, and let the machine complete its
So, a long story, but something to try if your machine ever gets into
this mode of misbehaviour.
Hope it helps.