AR15.Com Archives
 Junction Box Wiring For Dishwasher Melted and Burnt
57Strat  [Team Member]
9/21/2011 11:58:22 AM
I have a Bosch dishwasher. The other day I smelled something burning while the dishwasher was running. I thought it might have been some Tupperware in the dishwasher. A few minutes later the dishwasher stopped running and appeared dead. The repair guy came here and found that the wiring in the junction box inside the dishwasher was melted and burnt, with the wire-nuts melted. The only thing he could find wrong is that the hot water line going into the dishwasher was clogged with calcium sediment that obviously came from my hot water heater (it looked like white sand granules). He trimmed the wires and reconnected them, and cleaned out the hot water line, and the dishwasher appears to be working fine now.

My concern is I am wondering if a clogged up water line could have somehow made the water pump in the dishwasher draw too much current to the point that it melted and burned the wires? I am concerned there may be another problem that could burn my house down. Any ideas?

UPDATE: Apparently there is a recall on my dishwasher for this exact problem. Thanks for the IM, Lomshek. He didn't want to waste post 1000 in my dishwasher thread.

UPDATE 2: Bosch is sending out a tech to my house to check out the issue.

http://www.cpsc.gov/cpscpub/prerel/prhtml09/09100.html

http://www.bosch-home.com/us/recall.html
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redneck55  [Team Member]
9/21/2011 12:08:05 PM
Was the repair guy a plumber or electrician?

The breaker didn't flip? How old is it (the breaker)?

What is the amperage requirement for the washer?

First thing I would check for a crack in the heating element.

I wouldn't run it until I found out why this happened.

57Strat  [Team Member]
9/21/2011 12:15:19 PM
Originally Posted By redneck55:
Was the repair guy a plumber or electrician?

First thing I would check for a crack in the heating element.

I wouldn't run it until I found out why this happened.



I have no idea what the guy's qualifications are. The place where I bought the dishwasher sent the guy out to repair it. The repair guy said that the dishwasher pump would draw higher than normal amps if the hot water line was clogged, and this could cause the wiring to overheat and melt at the dishwasher junction box. Is that possible?

The breaker is 15 amps and it did not trip. The house and dishwasher are 5 years old.
SuperJanitor  [Member]
9/21/2011 12:17:27 PM
You either are running too big of a breaker or too small of wire.
learath  [Team Member]
9/21/2011 12:18:08 PM
Originally Posted By 57Strat:
Originally Posted By redneck55:
Was the repair guy a plumber or electrician?

First thing I would check for a crack in the heating element.

I wouldn't run it until I found out why this happened.



I have no idea what the guy's qualifications are. The place where I bought the dishwasher sent the guy out to repair it. The repair guy said that the dishwasher pump would draw higher than normal amps if the hot water line was clogged, and this could cause the wiring to overheat and melt at the dishwasher junction box. Is that possible?

The breaker is 15 amps and it did not trip. The house and dishwasher are 5 years old.


Melting wires takes a lot of current, on the other hand, if you've got the bare minimum possible wire and wire nut, there will be a lot more heat than if you use a reasonably oversize wire. Melting wires worry me.
ceverett  [Team Member]
9/21/2011 12:21:57 PM
Probably a poor connection that heated up. Either in the wire nuts, or on the screw terminal block.
57Strat  [Team Member]
9/21/2011 12:22:00 PM
Originally Posted By SuperJanitor:
You either are running too big of a breaker or too small of wire.


Do you think I need to ignore the obvious problem that this issue happened at the same time that the hot water line was almost completely clogged? The was about 3 inches of sediment clogged in the line where the line hooks to the dishwasher.
GST  [Member]
9/21/2011 12:39:08 PM
Originally Posted By ceverett:
Probably a poor connection that heated up. Either in the wire nuts, or on the screw terminal block.


This. If the problem was the motor locked down, the breaker would have tripped long before the wire heated up.
callgood  [Team Member]
9/21/2011 12:45:46 PM
When you get your dishwasher straightened out start shopping for a new water heater.
ceverett  [Team Member]
9/21/2011 12:46:40 PM

Originally Posted By 57Strat:
Originally Posted By SuperJanitor:
You either are running too big of a breaker or too small of wire.


Do you think I need to ignore the obvious problem that this issue happened at the same time that the hot water line was almost completely clogged? The was about 3 inches of sediment clogged in the line where the line hooks to the dishwasher.

A plug in the hot water line would just mean that it would fill slowly. The dishwasher pump is for drain and circulation. I can't see the method by which it would cause an electrical fire/meltdown.

That being said, significant buildup of sediment is a problem that should be addressed for the health of your plumbing system.
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