RDDB301 Viking Dishwasher leaks/overflows

JackJ

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Jun 23, 2011
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Wisconsin
Model Number
RDDB301
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6-10 years
I had piggybacked on an older thread yesterday, but thought it best to start a new one.

While running a regular wash water started leaking from under the front left. After stopping it and trying to re-start, receiving 1 flash for each of the Normal and Pots-Pans lights, indicating Moisture Sensor Disconnect, due to a reading being "out of range". Caused from Wires Disconnected to Sensor in Base Pan, Defective Moisture Sensor, or Defective Control Board.

But, I'm believe that it's simply water in the Base Pan that is causing the out-of-range reading. I can even still see some water on the floor, from the overflow chute.

Am I correct in my thinking, that the error code is likely merely telling me that there's water in the Base Pan, and that what I need to figure out is why. Elsewhere in the service manual it says that's caused from a leak or overflow. How should I go about trying to address that? I cleaned the filters (nothing of note found, though). Any other thoughts?
I don't have a garbage disposal, so the air line goes right up to the Air Gap on the sink. I tried blowing that out, but didn't notice anything. If that were plugged, would that have caused an overflow?
How would I go about checking for a blocked drain (I presume that could have caused it?) When I reset the machine, a second later it re-triggers the code.
If my pump had failed to drain, wouldn't that have thrown a separate code?
 

JackJ

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And if I need to drain the pan in order to not keep getting the Moisture Sensor code, is there a way to do it without removing the pan (which involves pulling the unit out and laying it on its back)? If I shopvac from the bottom of the inside of the unit, will that get it (or enough?)
 

Jake

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Hi Jack,

I haven't had training or worked on any Viking dishwashers.

Hopefully another tech. that has can help you out here.

Jake
 

JackJ

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Thanks, Jake. Fwiw, this might be a more general (non-make specific) issue, too, of what might be the source of a dishwasher leaking or overflowing, such that water gets into the base pan. I'm thinking that most makes/models have a similar setup in regards to that.
 

Jake

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Ok, since you put it that way.:)

Here's the basics on all models I work on: Whirlpool, KitchenAid, Maytag, Amana, GE, Frigidaire, Estate, Roper, Crosley, Kenmore.

On all these models I work on there is a float switch to keep it from overflowing, did you check that to if your float switch is stuck? Did you check the float itself to make sure that's not broken?

Also check the lower spray arm for cracks in it, that can make it leak too.

Check the door gasket for breaks in it? Check the bottom door gasket too? Some models have a bottom door gasket, some don't.

Check the tub itself for leaks in it?

Jake
 

JackJ

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Awesome! Thanks much, Jake! I had not checked those things; will now. Much appreciated.
 

Dan O.

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Maybe by Asko?

Jake; said:
I haven't had training or worked on any Viking dishwashers.
I read somewhere that some Viking d/w models were made by Asko. I have no experience with Asko so I can't tell by looking at its parts list whether the OP's might be one or not.

Dan O.
 

JackJ

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Location
Wisconsin
Just now getting around to this. My Viking was made by Asko. And the Service Manual doesn't list a float switch. But, I've got more info which likely targets the issue.
I'd turned the power off, which reset the error, and ran another empty load. It drained right out of the air gap. I don't have a disposal, so my air gap goes solely to the dishwasher.
I presume this means there's a clog in the drain, which must be underneath(?) the dishwasher.
My question is: do I need to pull it out, or should/can I try clearing it from inside? Is it ok to use lye-based cleaner to do so?

Thanks again!
 

JackJ

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I see that it could also be a clog from the drain motor assembly, so I guess I need to start there. Thanks for any other thoughts or tips!
 

Dan O.

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If water is coming out the air gap the clog is between the air gap and the house plumbing, most often at a sink drain. Start there.
 

JackJ

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Thanks, Dan. My air gap doesn't connect to the house plumbing, though; at least not under the sink, where normally it does to the garbage disposal (I don't have one). Perhaps it does behind the dishwasher, though; I haven't pulled it out yet.

Here's a picture of under my sink.

20190306_133014.jpg
 

Dan O.

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That's different. It isn't that skinny white hose is it?? I don't think that is sufficient for a dishwasher drain.

In any case you're going to have to get to the end of it and clear the blockage.
 
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