Thread: Bosch SHU43C shuts off in mid-cycle

turn off power at the breaker and remove toe kick panel. on left front is power connections- many fools install with wire nuts facing down, allowing water(soapy) to short out the connections. normally it blows and stops working at all. what's up with the rinse agent dispensor? is the cover closed and stay closed for the entire cycle? was it ever open during wash, causing excessive bubbles- which needs to be flushed out before it'll work correctly(dry all water from sump area, get a gallon of water, pour it in and start any cycle which will initially drain, then cancel/drain cycle. repeat until no foam inside when washing. the ntc sensor may be bad- washer's waiting for temp to be achieved before advancing, adding additional minutes to program, but never getting there, leaving wash water in sump. and you guys gotta give complete model #'s, serial #'s help also.

Bosch SHU43C 05UC /17... my dishwasher has similar issues to this thread. It often won't start at all, generally quite soon after a previous load has just finished running. Sometimes it will stop mid run.. remain off for anywhere from 15 to 60 minutes, then continue. We think its an overheating issue (no really scientific evidence). We have experimented with reseting the circuit breakers when it happens to no avail (we think). Alos, there are time when the 28 minute cucyle (we always use that one) will begin showing 29 minutes, sometimes 25, some times 23 etc etc.. but rarely 28. When I tried the test referred to, pressing power scrub and regular wash down before pressing ON/OFF to ON, nothing happened... all lights remained off, but when I release the power scrubb and regular wash buttons, the machine simply began the quick wash run at 28 minutes (or close to). There was no "test result". The machine still works, when all is said and done so we're running with "ain't broke don't fix it" but with a sense d-day approaches. Any ideas as to what might be wrong or what else I might do/test to provide more evidence on the exact problem ?

Many thx for any and all commets.

I have never had a unit fault this way. The main problems are usually: stuck wash motor; leaking wash motor; control board heater relay solder failure (re-solder); NTC failure; heater water flow pressure switch failure; fills and surges- drain and fills continuously, due to diaphram blockage; dispensor issues; and a few others.

The time of the display varies due to operational conditions. It will go up or down dependant upon things like incoming water temp, how clean dish water is, etc...

I would suspect the drain pump- due to it being the last and first thing run during cycles. It also needs to run, I believe, in order for the washer to begin a cycle: no run drain pump usually means no water will fill. The drain pump is way cheaper than the wash motor and much easier to change. You can get into sump area, uncover drain pump impellers on the left-torx screw I believe or a tab, about 9 o'clock, and check for glass(glass is clear- be smart) or junk under/around plastic blades, and also "flick" blades with your finger- the blades should "lump" around on rotation, not spin freely like fan. Drain pump can be replaced thru front panel but: TURN OFF POWER BEFORE PLAYING! Good luck.

thanks ivoid. you're dead right. I checked the drain entry.. no blockage, no dirt and the fan spun as you said... all very clean. we ran it and it stopped after 3 minutes (which my wife said its been doing for a few weeks now), so we opened up and saw a good build up of water in the bottom, well above the highest point mesh grate..so I pulled off the mesh and lifted the basket out and it drained, gradually but not completely, and when I closed it the cycle took up where it left off.... I guess this suggests, as you said, the drain is the culprit, no ? motor lost some power ? there was no great chunk of anything in either the top mesh or the basket..

further observation. when the program is finished, there is always water left in the sump area a good inch or two deep at the bottom of the sump... what might this mean ? is it that the drain pump is working but not its full cycle ?, or perhaps there's blockage beyond the accessible area ? (seems unlikely though, considering all the filters.. can it be hard water detritus creating back pressure that stops the last couple of inches ?)....

Unrelated to the problem (I think)... there's always moisture on everything when we open the machine, even the next morning... is this the product of a little water left in the sump or is it that there's no dry cycle and moist hot air condenses ?

if I am to eventually replace the drain pump, you refer to the front panel... by that do you mean I remove the panel of stainless steel on the inside of the door and get at it that way ? or is the pump underneath so the panel is at the front facing out at floor level ? would that mean the whole machine needs to be "jacked up"..to allow space to work ? (its a built in unit... not sure how I'd do that).

many thanks for your feedback and appreciate any and all comments !

Do this: disconnect the drain line under the sink and run it into a bucket. Also, said drain line should have a "high loop" before connected to drain= important, and many are incorrectly installed without the high loop. So, with drain line in bucket, initiate cycle and drain pumps out. To replace drain pump you need to remove the toe kick and then you have access to the guts underneath.

As for "wet" inside- I would suspect the real problem is the heater relay contact. It probably has "un-soldered" itself. The water gets real hot on last rinse and the residual heat dries the dishes- when the heater doesnt work, you get forever programs and not finishing cycles, water in bottom or doesn't dry dishes. Easy to resolder the board with a low temp soldering iron. You will melt the board if not low temp. Clean up contact area and resolder it. I would suspect this is your real issue. To check heater relay- you need to remove the front ss panel, the control panel, and carefully release the control board from steel frame, open up plastic cover and flip main board over to see the melted solder contact. Turn off the power before playing....

I think there is posts on how to fix circuit board heater relay issue. Good luck. Can buy a new board, but usually they are repairable if only needs solder.

Hi ivoid. thank for your quick response. and you're right, no high loop (it actually has a low loop... droops down low in a big loop and back up to its join with the kitchen sink drain pipe). fixed that with a high screw and a hook to hang it from.

What am I trying to get done by taking the drain line off and running a cycle into a bucket (happy to do it).. just wondering what that will establish ?

Also, I'm a little confused. Do you think I need a new drain pump ? Do you think the drain pump is not working properly on account of residual water in the sump, and I should necessarily replace it ? Or were you just answering my question about how to get at it ?

Thanks for the info and advice on the heat relay.. I did see some pictures done on macro about that so I'll get at it. Makes sense.

I just erased my reply by mistake- arrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrg

Hey GC GT3,

Shorter version sorry- Checking drain line into bucket for debris was for "air-gap" type drain connections. If yours goes directly to disposal or plumbing= nevermind.

Residual water pools in sump due to no high loop.

First- run the dishwasher on normal cycle, making sure the rinse agent dispensor is full. When it is finished washing and starts drying- pop the door open and check for steam escaping. NO steam equals no heat, equals long program runs with poor drying.

No heat causes: heater relay solder fail; NTC failure (temp sensor can be ohmed); flow switch failure; broken wire in harness

So run it and report back- I would suspect it is the solder connection for heater relay.

-voided thrice

I would also suspect it is the solder connection. How old is the appliance?

hi ivoid.. long time since i checked in about my Bosch problems per thread above.. had to go down under to attend to some family issues. so back on deck now, never got at the solder in the heat relay contact.. whenever a cycle runs, if we open the door shortly afterwards, we're hit by a wall of steam, so no lack of heat being generated.

Current problem is that the machine has no power.. its been three days now and no light ever appears on the on/off switch.. dead in the water so to speak. Our problem back in September, which was never remedied, (I'm assuming you can read the thread above.. lemme know if not and I can cut and paste) was that of the machine simply refusing to start on occassion, but with the passing of time it would always somehow get its act together and run. So we're clueless as to what to do less. Checked the cicuit breaker a number of times. ALl other electrical things are running fine. Checked the sump; couple of inches of water in it but no blockage. Tried the test sequence but with no power when I push on/off, nada. I noticed the drain tube loop was looping low (fell off the hook I installed).. Any ideas ?

Many thanks.