Introduction: Fixing Bosch DishWasher

Picture of Fixing Bosch DishWasher

So my home dishwasher had been acting up for about a year now.  It just started to get worse so I decided it was time to fix it.

Problem:

Dishwasher would start, run for about 5-10 minutes, and then shut off.  It would stay off for about 20 minutes, where it would then restart where it left off and finish the cycle. (after doing some research i found that some people with a similar issue reported that their washer would continue to run and never shut itself off at the end of the cycle)

Analysis:

I ran the test cycle by pressing and holding the REGULAR WASH and RINSE AND HOLD buttons at the same time while turning the washer on.  Then press the same two buttons again at the same time to enter the test cycle. ( your buttons may be different )

Once the test cycle had finished it was displaying the error code on the 7 Segment Display.  Mine was "1" which meant there was an issue with the "Aqua Sensor ("Sensotronic")".

I assumed this had to do with the heating cycle of the water, because it seemed like the washer would always shut off when it should be heating the water or immediately after heating the water.

I determined that there may be an issue with the main circuit board, and set up to disassemble the washers main panel.


The following will document each step I took.

Step 1: Remove the Front Panel

Picture of Remove the Front Panel

There are just a few screws that remove the front panel of the washer.  The screws are along the inside edge.  Once you remove all of the screws the front panel comes right off revealing the wiring up to the control panel.

Step 2: Removing the Control Panel

Picture of Removing the Control Panel

Removing the control panel was the next step.  A few more screws along the same line as the front panel removed the control panel. We had to carefully remove it and then unplug each of the wire clips to get better access to it.  These pictures were important to have so we can refer back to them while re-assembling the washer.

The red and grey 2-Conductor clip in the middle was power.  Even though we had disconnected the power in the beginning I disconnected this one first in case there was any stored power within the system.  The rest are signal lines.

Step 3: Removing the Main Processing Board

Picture of Removing the Main Processing Board

The main processing board is located inside of a heavy plastic container.  you just need some gentle hands to press the plastic clips along the sides to release the back of the container.  It will then swing up giving you access to the main processing board.  There are a few more plastic clips that hold the processing board.  Find them and careful push them aside with a screw driver while lifting the processing board.  You must be patient not to break the plastic clips, they are fragile.  

Once the circuit board was removed we could analyze it a little better.

Step 4: Analyzing the Circuit Board

Picture of Analyzing the Circuit Board

Looking at the circuit board we found one solder pad that had been cracked.  It's a little difficult to see in the pictures, but you can tell when you looked closely that there is a visible ring around the bottom of the solder joint.  This slight crack will disconnect the part from the board.  My guess is the manufacturer used Lead based solder that was getting heated up and cooled again every cycle, and eventually just cracked.  

I re-melted the solder and removed it completely with a solder sucker.

I then re-soldered the pad with new fresh solder.

I also touched up a few other pads that looked a little messy (didn't want them going bad in another month)

Step 5: Putting It Back Together

Now just the reverse of taking it apart.  Taking our time we put each piece back together the same way we took it out.  Wired everything up and put the control and front panels back on.

We flipped the power back on and started some cycles

So far the shutting off issue hasn't happened again



To put this repair into perspective:

If we had called the company they would have sent a repair man, probably would have cost $50-$100.  He would have then said it was a processing board issue and that he would have to buy a new one, that's another $200.  He would also then need to come back out to put the new board in, another $50-$100.

In the end this 30-60 minute repair may have saved about $400.

Not a bad number to me!

Comments

Jack8484 (author)2013-03-10

I found a video on YouTube that shows how to repair a control board with a bad relay! The board being repaired has a 6V relay. Mine uses a 6V relay too and the R46-5D12-6 relay fixed it. If your board has a 12V relay, then the R46-5D12-12 relay would be the one for you.
http://www.youtube.com/watch?v=Jb8gAnMb2zQ

Excellent recommendation, I found this video spot on for showing how to replace the heater relay on the control board...Thank you Jack8484!!!

AndyGadget (author)2012-08-13

The other major fault I've seen with the Bosch washers is the emptying pump motor weakening and failing.  Symptoms are it will fail to complete the washing cycle, stalling at the end of the various phases. 
I replaced my pump motor after 6 years of good service (a reasonably easy job) and shortly after that the diverter motor failed (which alternates between top sprayer and bottom sprayer). That requires just about a total strip-down, so I replaced the washer - with another Bosch.

BooRan (author)AndyGadget2012-08-13

It's interesting you say that. About a year or two ago (before I was on instructables) my motor failed. I actually got to the point of disassembling the motor, found the disk inside that had broken, and replaced that part only. Put the whole thing back together and it ran fine until this electrical issue.

Talk about never giving up!

AndyGadget (author)BooRan2012-08-13

The problem with mine was the little induction motor, and the same on the diverter.  Those things always seem to be under-specced for the job and fail in a variety of equipment.  My most recent one was on the central heating T valve.

BooRan (author)AndyGadget2012-08-14

yea, It's a shame such an expensive appliance seems to fail so easily.

ckoehler1904 (author)2012-08-13

BTW, The recall MAY apply to your Dishwasher even if it is WAY out of warrentee - dafety and liability issue for Bosch. Other than that they make a terriffic and QUIET dishwasher...

BooRan (author)2012-08-13

ckoehler1904 has asked me to relay this message:


"Your Bosch Dishwasher MAY have been recalled!
Hi, I tried posting to your instructable but it would not allow me to do so. Very good Instructable. However, by pure coincidence, I JUST had my Bosch DW repaired for free as part of a safety recall - several fires caused by defective controllers. From the picture on your site, it appears that we both have the exact same model - mine is SHU43C06UCCCCC/17, and there are 8 other models which are also part of this safety recall. The recall models can be found at www.boschappliances.com or by calling 800-856-9226. If needed, they will send out a replacement part and will provide replacement totally free - or give you credit of several hundred $$s for a new DW."

BooRan (author)BooRan2012-08-13

A link directly to the Recall Check:

http://www.bosch-home.com/us/support/safety-notices/dishwasher-recall.html

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Bio: Electrical Engineer, control systems, automation, small electronics, home automation, microcontrollers etc.
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