Bosch SHX43C05UC/43 runs continuously, won't complete cycle

[foliage]

Hi, I've had good luck with this community over the years, hoping I can get some more help. I've got a Bosch SHX43C05UC/43 dishwasher that runs continuously. The cycle is supposed to last 105 minutes, but it'll run for hours if we let it keep going. The water doesn't seem hot, either. I've done all the googling and searching I can and my best guess at this point is that the water level switch has failed or heating unit is dead. A few notes on what I've done so far:

1. I've had a heck of a time figuring out the diagnostic cycle on this unit. It doesn't have any kind of digital display, so the error codes are displayed using a combination of lights on the control panel.
2. I might have figured out the diagnostic cycle and if so, perhaps the code I got back indicated that the water level switch failed. But TBH, I can't be sure as my model wasn't listed in the manual and the instructions for running the diagnostic cycle were a little unclear.
   
   NOTE: I have the diagnostic document for the SHU43 and SHV43 models which I figured would be close to the SHX43, but the diag info they mention for the SHU/SHV don't fit the dishwasher (I have a "delicate/econo" cycle that those units don't seem to have). I found a section in the doc for SHU 991x UC/12 (Integra) models that seems to fit my unit. The instructions for running the diag cycle are not very clear, so I'm not 100% sure I'm doing it right, but when I run the diagnostic it comes back with the "regular wash" button lit. The manual says that this is a "Water filling fault (over or under filling)" .

So my question to this group: Is there any way I can further pinpoint this issue? The possible parts I'd need are not cheap, so it's not really worth it to throw a bunch of new parts at it and hope for the best (spray and pray, if you know what I mean).  

Thanks!

 

[certified tech group 51]

For a Bosch with long cycles, cold water, I would remove the control unit, access the board inside and check the solder connection for the heating circuit on the board.....The unsoldered terminal will probably be on a relay...just resolder, reassemble and test...

[asteysn2]

cHECK THE HEATER relay solder connection on the board

[foliage]

Thanks, guys. I'm aware of this particular root cause, so I'll pull the board and check it out. 

[foliage]

One other question - I can't find any troubleshooting guides or repair manuals for the SHX43C05UC (or anything in the SHX series). Does anyone know what other Bosch models the SHX models are similar to?

For example, I found a repair manual for the SHU series and the configuration of the SHU series seems similar to my SHX unit. But I can't find any repair manuals for the SHX series. If I knew that the SHU was basically just the SHX with some small differences, I could use that manual to further diagnose this dishwasher. Thanks for any thoughts.

[foliage]

Well, you guys know your stuff! I pulled the control panel and sure enough, there was a big burned spot one of the solder joints. I dropped some solder on the joint, put everything back together and tested and it's all fixed! Here's a before / after pic in case it helps anyone else: 

https://imgur.com/a/GYTsYAx

Thanks a ton for the help on this.

[Rallye455]

I’d like to thank you all for this awesome post. We’ve had our Bosch for over 13 years and it had been fantastic. A month ago it starting running way too long. I searched and found this site/post. The pics you posted Foliage were extremely helpful. It’s running great again and thanks again!