Bosch dishwasher will not finish cycle

MrMark52

Premium Member
Joined
Feb 28, 2011
Messages
2
Location
East of Dallas
Model Number
All models
Brand
Bosch
Age
Less than 1 year
Many of you may have come to this site to find out why your Bosch dishwasher will not complete it's cycle and finish. Additional symptoms are the dishes are warm, but not hot, and if there is a countdown display on your DW, it will never count to 0 and end the cycle.

Most normally, this is due to a burned area of the printed circuit board inside of the controller. This is a well documented failure, even to the point that Bosch has a tech bulletin out that explains that a repair for this is to "refloat" the damaged area with solder.

However, this is only a temporary repair at best. The cause of the burned point on the board is due to an undersized relay. From the time the dishwasher is first used, the undersized relay contacts begin degrading and carburizing. With each wash cycle, more carburzing causes increased resistance of the contacts, which result in heat. The heat is conducted down the metal reeds inside the relay, which get hot enough to melt the solder. As the solder begins to melt away, the connection between the connector pin on the relay and the printed circuit board begins to intermittently fail, to a point that it will arc and burn at the failed point on the circuit board.

The ONLY correct solution is replacement of the relay with one rated for the duty. This is true when repairing the board, or when choosing to purchase a new board (of all the boards I have repaired, I have not seen any where Bosch has upgraded their design).

I maintain a stock of the various relays used by Bosch on this board, with quick turnaround of just a relay, or a repaired board (I even buyback any boards you may have). These timer boards are also used on a number of different manufactures dishwashers, so if your timers looks anything like the Bosch units, the repairs are the same.

Contact me for more information at boschrepair "at" tx.rr.com .
 

rte cat

Premium Member
Joined
Nov 25, 2009
Messages
18
Location
Michigan
Where can I get a heavy duty relay for my Bosch dishwasher? it is model # SHU43C0
Thanks,
Vance
 

MrMark

Premium Member
Joined
Sep 24, 2007
Messages
6
Location
Dallas
Just to update anyone who reads this thread, I am still upgrading the heater relay for these controls. Please email me to the above email address, or PM me here.
 

BoschLorne

Premium Member
Joined
Feb 7, 2018
Messages
2
Location
New York
I am looking to replace my dishwasher and want a Bosch but have seen too many alarming posts. I like the look of them and how quiet they are but still hope there's hope to get one! Saw the 800 from boschdishwasherreviews.com and think it's what I want but want to make sure i make the right decision.
I'm not too handy so don't want to have to fix it myself once the warranty runs out :p
 

MrMark

Premium Member
Joined
Sep 24, 2007
Messages
6
Location
Dallas
BoschLorne,

In my opinion Bosch makes one of the best dishwashers out there. The only significant issue that I know about is the heat relay issue. Your concerns are probably misplaced because of the dreaded Internet and the fact that most people will complain before they praise.

And FWIW - I have no association with any manufacturer - but I have years of experience with machine/appliance/equipment design. And I happen to own a Bosch dishwasher that had a failed heat relay. After an initial "will not finish the cycle" failure, I set out to figure out why the relay failed, figured it out, upgraded the relay, and our Bosch dw has been working happily ever after since. We bought ours in 1998 and it is still going strong today. The only other issues that I've had with it are the recirc pump got stuck a few times (but has not done that in years, at least since 2011, and easy to fix with a nut driver), I've replaced all the hoses as the main drain hose sprung a leak, and the door seal (because I wanted to - the old one was getting gummy and looked like it was failing).

So, purchase with confidence in your decision. Quite frankly, the more you research different brands, the more you will become jaded to the reviews and comments, especially when it's hard to distinguish honest comment from advertising.
 

r55

Member
Joined
May 11, 2018
Messages
1
Location
Seattle
Just to update anyone who reads this thread, I am still upgrading the heater relay for these controls. Please email me to the above email address, or PM me here.
Do you know if this defect still exists in newer Bosch dishwashers? I installed a model SHP68TLSUC/07 less than 3 years ago and had no problems until a couple of days ago. Now the dishwasher continues to run until is it manually stopped, the countdown timer never advances beyond a point early in the countdown (for example, it will stick at 2:20 in a cycle that should take 2:35) and the dishes are not hot when the dw is stopped. If the machine is reset (in this case by pressing the Start button for 3 seconds), it drains successfully.
 

MrMark

Premium Member
Joined
Sep 24, 2007
Messages
6
Location
Dallas
r55,

Everything that I've seen, the problem does still exist.

It's not a guarantee, but if you take the control board out and inspect it, if you don't see a burned solder joint under one of the relays, look for discoloration of the copper associated with the relay that connects to the 2 or 4 pin connector (has 2 or 4 1/4" male spade connectors inside of the board mounted connector). It takes a trained eye to see the slight discoloration (if it there is any). If you don't see it, it doesn't mean the relay is not bad as they can fail internally before causing a lot of heat to be conducted to the board.

There are really only 4 things to go wrong here, and 99% of the time, it's the relay (the other 3 things are a bad temp sensor, a bad heater, or a bad flow switch - but I rarely have encountered it being one of the other 3).

PM me for more info as I can fix you up!

Mark
 

DEW64

Premium Member
Joined
Sep 13, 2018
Messages
2
Location
Northern Virginia
Thanks for posting that info. about the relay. We had 3 breaker trips in a row this week from some guys doing some heavy duty drilling on some exterior work & using an outlet on the same breaker as our kitchen :(…Now the countdown seems to be wonky & our dishes aren't getting clean in our SHE55PO5UC. There is water, but doubt there's heat, as the dirty butter dish still had butter on it!!! I’m thinking the relay is shot?? Or do you think I need to replace the entire control board? Thanks again, Mark, for any insight!
 
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DEW64

Premium Member
Joined
Sep 13, 2018
Messages
2
Location
Northern Virginia
r55,

There are really only 4 things to go wrong here, and 99% of the time, it's the relay (the other 3 things are a bad temp sensor, a bad heater, or a bad flow switch - but I rarely have encountered it being one of the other 3).


Mark
Hey Mark - I changed out my entire control board & still dishes aren't getting cleaned. You mention 3 other possibilities above....Any guesses as to which it might be? Not super hot, but water seems to be adequate.

Thanks,
Debi
 
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