Dishwasher problem

[GB]

The dishwasher pump is continuously running, even at the end of the cycle. Does anyone have any idea what's likely to be involved in fixing this?

As far as I can tell, the pump is working fine. There's no water in the machine. The filter is fine. I could test whether water gets pumped out okay.

It's a Bosch SGI45E15GB. I was wondering whether a float switch might be stuck? If so, how easy is that to get to?

I've got nothing to lose by trying to repair it, really, as the machine is 11 years old, and a Bosch repair would cost £110 plus parts. It's been run more than once a day on average, so I suspect it might be deemed unrepairable. So, I've ordered a replacement, but I can easily cancel that.

Any advice gratefully received.

[GB]

Oh dear. Isn't that a pretty expensive component, even if it's available?

[tabbypurr]

sounds like a switch contact is stuck on or a triac shorted.

NT

[RJH]

I've just checked for the spares for my 12 year old Siemens (Bosch) dishwasher on the Bosch web site - all the major parts seem to be available, and cheaper than the likes of espares clones on the small selection I looked at. Also just bought some filters/bags for my 15 year old Bosch hoover - looked as though things like the motor and chassis parts also available.

[Tim Watts]

Water level sensor (if it doesn't rely on a simple timer)

More likely - if it pumps all the time and will do nothing else:

There is a drip tray underneath many makes of dishwasher, with a float switch - this is supposed to detect leaks and go into emergency pumpout mode.

It can accumulate minor leaks (perhaps a little water getting past a door seal) and fill up - it takes very little as the float sits in a slight recess in the drip pan.

Pull dishwasher out, having emptied. Tilt to one side about 30 degrees and hold there for 30 seconds to run off any water in the tray.

Test.

[Bob Eager]

I suspect that's the labour and parts price.

[Andrew Gabriel]

I presume you are referring to the drain pump, and not the wash pump?

Some dishwashers have a leak detection system which is a drip tray spanning the bottom and a float. If the tray catches enough to trip the float, the machine switches everything off and the drain pump on. That could explain the state yours is in. You will probably have to take off a side or rear panel to see in the tray. Alternatively, you could try tipping the machine to see if the tray spills out, but you might end up pouring the water into some electronics which does even more damage. If left for a long time, the tray may dry out by itself - this can happen when a machine stops working and is left for ages before being fixed, and then found to work without anything having been done to it.

A common problem which generates a non-fault leak is something such as a piece of cutlery caught in the door seal during a wash, with the resulting leaking water eventually triggering the leak detection.

[Brian Gaff]

Float switch stuck, ith detritus. I hate dishwashers. I won't have one here. Its a silly device that has you washing things first before you put them in, which is really rather silly. I'll await a true dish and cutlery washer where you can shove filthy dishes in one end and get sparkling clean ones out the other. Brian

[F]

As I posted on a previous thread: there's excellent help and advice at

[John Rumm]

Had something similar happen on our Miele dishwasher. There was small leak into the water conditioner due to an O ring hardening with age, and that would after a few washes put enough water in the drip tray to disable the machine.

Yup that worked as a temporary workaround on ours until the new O ring turned up.

[RJH]

That's precisely what they do! You're supposed to scrape waste into the bin, but that aside, nothing to do.

I can't th> Float switch stuck, ith detritus.

[Tim Watts]

I have a Miele that does this about once a year. I've had it on its side and drip pan off and I could not trace any leaks from any water bearing parts - it was very confusing and remains a mystery still.

[TimW]

This is good advice. The same with Neff-Seimens-Bosch. When you first start the machine the pump-out sound you initially hear is the self testing of the pump on the floor level drip tray . The switch can get stuck.

TW

[GB]

Thanks, Tim. Your diagnosis was indeed correct! :) Lots of water spilt onto the floor from the sump, and the machine is working again.

One other issue I found was that the drain hose had become kinked and had developed a couple of small holes. I suppose those were closed up inside the kink until I pulled the machine out. Anyway, I have patched it up with self-amalgamating tape reinforced with duct tape. How long will that last?

[GB]

Thanks. I think that's what has happened. The door seals are not too great after this many years.

[Tim Watts]

Cool -

Your main test now is will it fail again in a non trivial time.

If it does, you might actually have a real leak that's worth having it slightly to bits for - if not, minor problem or a "heisenleak" like mine :)

[tabbypurr]

What stops dishwashers doing that is the green water wasting legislation. Dishwasher water use has gotten so low that they don't rinse properly, so it's now common practice to prerinse most of what goes in, resulting in far more than 10x as much water use. Oh look, it's politics again.

NT

[John Rumm]

Many of them also use the hose in a hose technique for the fill hose (with the actual water inlet valve screwed right onto the service valve at the house end rather than inside the machine).

That way any leak in the feed hose is also collected and fed into the sump tray (and the float switch interrupts power to the fill valve - thus preventing a possible flood even if it happens in the fill hose).

So if there is not obvious leak in the machine itself, it could be on the inlet hose.

[Tim Watts]

Oh - I knew about the magic hose, but I did not realise that was how detection was achieved - cheers - something I can look at closely if it happens again...

[Steve Walker]

The same problem but in a different format: our old machine didn't have a tray or a float, it simply had a microswitch held open by a piece of dry sponge. When wetted, the sponge would soften and compress, allowing the switch to operate. Over years the continuous pressure from the microswitch lever gradually squashed the sponge and triggered despite there being no water under the machine.

SteveW