[john1970]

To all AC'ers

2.5 years ago I purchased a Bosch dishwasher model SHU43C.  This past Saturday it stopped working.  I immediately turnoff the circuit breaker and inspected the electrical box on the dishwasher.  To my suprise and horror the insulation on both the neutral and hot leads was burnt and the wire nuts used to make the hardwired connections were completely melted.  The box was covered in black soot. 

THIS COULD HAVE READILY CAUSED AN ELECTRICAL FIRE!! 

Has anyone here ever had a similar problem with their dishwasher?

In the future I know I will not purchase another BOSCH applianance and I will only wash the dishes when I am at home.

Best,

John

[topround]

I have a Bosch dishwasher and have not had any problems.. yet.
I find the quality to be a little lacking. Being a german machine I expected more. My previous dishwasher was a Miele, a much, much better machine than the Bosch, and it had built in water softening for those areas that have hard water. Bosch carries a certain prestige to the name but in reality it is no better than a Maytag or Kenmore. Spend a few hundred more and get a Miele, or save a lot and buy a Maytag. Steer clear of Bosch appliances, they are resting on their laurels of the past.

[bubba966]

To all AC'ers

2.5 years ago I purchased a Bosch dishwasher model SHU43C.  This past Saturday it stopped working.  I immediately turnoff the circuit breaker and inspected the electrical box on the dishwasher.  To my suprise and horror the insulation on both the neutral and hot leads was burnt and the wire nuts used to make the hardwired connections were completely melted.  The box was covered in black soot. 

THIS COULD HAVE READILY CAUSED AN ELECTRICAL FIRE!! 

Has anyone here ever had a similar problem with their dishwasher?

In the future I know I will not purchase another BOSCH applianance and I will only wash the dishes when I am at home.

Best,

John

John,

That's not the dishwasher's fault. That's the fault of whomever hooked up the electrical to the dishwasher.

Because whomever hooked it up didn't get the wire nuts tight when they made the connection. A loose connection not only doesn't transfer electricity well which introduces resistance which is basically heat. But a loose connection also allows air to enter the connection which oxidises the copper wires. And the oxidation also adds resistance.

Enough resistance and things melt and/or catch on fire.

Why do I know this you ask?

I know his because I'm an electrician. Many times I've seen loose wire nuts from someone not using them properly or using them in a sloppy manner. And they look just as you describe them.

I have no idea who it was that installed your dishwasher. But whoever it was didn't make a good enough electrical connection and that's what caused your problem.

[zybar]

FWIW, my last three dishwasers have been top of the line GE and two Bosch.

The GE broke down right after the warranty period ended (literally within 30 days of it ending) while I never had a problem with the two Bosch units.

George

[Carlman]

I had the same hunch that Bubba confirmed... I've installed a few dishwashers and I generally use electrical tape as an extra precaution even after properly implementing the wire nuts. 

Sounds like you are jumping the gun by condemning a successful company with this one un-researched incident.

-C

[bubba966]

Carl's post made me think of another possible, though less likely cause of what happened.

Did the wire nuts get wet from a plumbing leak?

That could also cause such a problem. But I doubt that was the cause as the electrical connection is off the floor just a bit.

Without seeing it myself I can't say for sure. But I'd be seriously good money on it being a bad connection with the wire nuts. Not so surprising to me. Especially since Bosch dishwashers are a bit of a pain in the ass to hook up electrically. I've not been fond of a one of them as far as hooking them up goes.


My advice is this. Assuming that just the wire & wire nuts were damaged clean the wires up to remove any oxidation. Make sure the wire is stripped to the proper length. Use the proper sized wire nuts for the size wire that you're dealing with. When puttin gthe wire nut on make sure that the connection is tight. If one of the wires is stranded copper and the other solid copper make sure that the stranded wire is sticking out a little farther than the solid wire before you put the nut on. That way the nut will grab both wires well. If you had a stranded & solid wire and the ends were the same length when you put the nut on the nut will frequently not grab the stranded wire leaving you with a loose connection.

[john1970]

These were the observations:

1) Both wire nuts were still secure to their wires, but both the nuetral and hot nuts were severly melted.

2) There was no water or leaks anywhere.

3) Insulation on both the nuetral and hot wires was burnt off for 2-3 inches.

Causes me to believe that something else in the dishwasher caused a severe current surge that caused the wire nuts / insulation to fail. 

I'm going to speak with Bosch tomorrow and see what they say..should be interesting.


Best,

John

[bubba966]

I didn't think that it was a water problem as that's highly unlikely.

I'm still going with a bad electrical connection at the wire nuts. Be it from the wire being oxidized before the connection was made, or that the connection was just made poorly, period.

Any type of current surge that would've been big enough to do anything would've tripped the breaker (unless you've got a Zinsco electrical panel as those are notorious for not tripping the breaker even on a dead short. Cutler Hammer panels will do that as well, just not as often as a Zinsco panel will).

Were the wires just scorched & black, or were they also actually melted (as if they were arc welded)? A high current draw will melt/destroy the wires as if they'd been arc welded, and that even will trip the breaker or blow a fuse. A long period or high resistance due to oxidation and/or a poor/loose connection will melt the insulation & blacken the copper and not trip the breaker or blow the fuse.

Also you said it stopped working and you had to shut the power off at the breaker to check it out. That right there says loose connection to me. I've seen that happen in all kinds of things. Switches, outlets, recessed lights, etc. A loose wire nut leaves a connection that's not tight and provides high resistance. The connection being loose causes oxidation to build up on the wires in the connection. After a while that loose connection will get hot enough to melt the insulation and blacken the wires. After it's done that the conductivity of the electrical connection gets so bad that the device either stops working all together or is intermittant in it working or not.

If you're wanting a little more peace of mind you can use moisture resistant/underground wire nuts. They're very spendy ($2+ each ) and aren't re-useable. So if you're using them you'll have to get the wires in there right the first time as you've got no second chance.

[Captain Humble]

Years ago while we were still in New Orleans we bought a Thermadore.
One of the guys on my dart team was a manufacture's rep so we got a really good deal.
At that time I think it was the only dishwasher that was all stainless steel on the inside.
That was a great machine.

When we built our home in TX we went with the builders standard appliances.
Noisey, no NOISEY!

We replaced it with a Bosch again all stainless.
It is dead quite and runs at temperatures that disinfect the dishes.
We love it and I'd buy another in a heart beat.

Thanks for the explanation Bubba.
I was a bit concerned before you jumped in.