Comments on: What did my dishwasher do?

Question: What did my dishwasher do?

SpacemanStix — Mon, 21 Jun 2010 17:22:35 -0800

I opened my dishwasher yesterday while it was off (not running and nothing in it), and there was a visible flash (about the size of a baseball?) near the front side by the door, and a sharp bang that seemed like it was a mini-ignition of some sort. No debris was left, and no smell lingered. I tried starting the dishwasher, and it seems to be fine.

I'm feeling a little bit worried, as I'm not sure if it's indicative of something serious. Does anyone know what might have caused it?

We haven't actually started used the dishwasher ourselves yet, as it's one that we inherited in a recent home purchase.

By: jedicus

jedicus — Mon, 21 Jun 2010 17:32:32 -0800

Build-up of hydrogen in the hot-water system?

By: sanko

sanko — Mon, 21 Jun 2010 17:40:32 -0800

Original, non-PDF version of jedicus' link is here

By: _dario

_dario — Mon, 21 Jun 2010 17:47:03 -0800

static? A short circuit? Is it grounded?

By: librarylis

librarylis — Mon, 21 Jun 2010 18:42:16 -0800

There was a recent recall of specific Maytag, Amana, Jenn-Air, Admiral, Magic Chef, Performa by Maytag and Crosley dishwashers purchased between 2006 and this year. They are considered a fire hazard.

If you have one of the models listed above, click on this link to see if the serial numbers match (Consumerist's a bit alarmist, but their information is correct); if so, shut off the dishwasher until you can contact Maytag and they will send out a repair person. Speaking as someone who was affected by the recall, it's really not a big deal so long as you turn off the dishwasher until it's repaired.

By: odinsdream

odinsdream — Mon, 21 Jun 2010 18:48:26 -0800

Seconding librarylis; we know someone affected by one of those recalls. Her dishwasher melted her silverware.

By: SpacemanStix

SpacemanStix — Mon, 21 Jun 2010 20:39:41 -0800

It's not a new enough washer to be one of the recalled units (I looked just to double check). It struck me as being some sort of gas buildup though, like when you ignite a propane grill that has been on for awhile, and it makes a big bang from the buildup. Which makes me think something along the lines of jedicus' suggestion.

What was weird, though, is that I didn't turn on the dishwasher. I simply opened it, and this happened. Would this be enough to ignite a gas?

By: fantabulous timewaster

fantabulous timewaster — Mon, 21 Jun 2010 21:14:21 -0800

Hydrogen has a very low minimum ignition energy and can be ignited by otherwise invisible sparks.

I'm surprised, though, by the claim that hydrogen buildup is an inevitable consequence of the chemistry of hot water heaters. Isn't that why plumbing systems have vent stacks that stick out of the roof? ... Looks like those are only on the waste side, to vent sewer gas.

By: SpacemanStix

SpacemanStix — Mon, 21 Jun 2010 21:20:02 -0800

Wow, I do wonder if that was it then. We bought this place about three weeks ago, and we've been letting things sit for awhile, as we make plans to move out of our other place, and clean up a bit. And it was sitting empty for awhile before that. We haven't really been using the hot water during this time.

So if this is correct, the answer seems to be to run hot water for awhile if things have been sitting for a period of time?

By: Kid Charlemagne

Kid Charlemagne — Mon, 21 Jun 2010 22:26:12 -0800

The hydrogen buildup isn't in the drain side - it's in the supply side. What's happening is that different metals in your plumbing system are creating a very weak battery and making hydrogen in the hot water tank itself.

By: fantabulous timewaster

fantabulous timewaster — Mon, 21 Jun 2010 22:47:51 -0800

I guess you could test it as indicated in sanko's link: rubber-band an empty garbage bag around a faucet, and see whether it fills up with liquid or with gas.

You could also try to duplicate what you saw using hydrogen you make from intentional electrolysis, as described in probably every kitchen chemistry book.

By: SpacemanStix

SpacemanStix — Tue, 22 Jun 2010 08:09:23 -0800

I'm wondering if this is something to bring a professional in for. But I'm not sure who you call regarding exploding dish washers.

By: jedicus

jedicus — Tue, 22 Jun 2010 08:30:55 -0800

I'm wondering if this is something to bring a professional in for. But I'm not sure who you call regarding exploding dish washers.

I'd start by calling a licensed plumber.

By: leapfrog

leapfrog — Tue, 22 Jun 2010 09:18:16 -0800

When my dishwasher was installed, the [EXPLETIVE REDACTED] who installed it routed the power cable through the middle of the hinge. Over time, the rubbing of hinge against insulation tore through the cable, presenting as first an increasingly flaky dishwasher and later total loss of power as the cable was severed.
On discovering this, I realized that this had been the most benign of the many possible outcomes. One possible outcome, I figured, was that the whole chassis of the dishwasher could have been connected to high voltage. Or it could have shorted the source to ground, causing a fire hazard. Only bad things can come of that.
If you happened to have the same thing going on under your dishwasher, you might see a big spark. It might ignite some dust under the dishwasher, causing what looks like a small explosion. So, I'd check on that, too. Turn off the power at the breaker/fuse box before you do, but check on it.