Dishwasher Causing Condensation Problem


Old 09-16-08, 03:44 PM
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Dishwasher Causing Condensation Problem

I posted yesterday about a condensation problem we have underneath our kitchen sink. Is it possible that this could be caused by a problem with the dishwasher? A guy at Home Depot suggested that. There is a copper pipe running from the dishwasher under the sink. There is no water around it.

Today I left the house with the underside of the sink dry. The dishwasher was running. When I got back, there was condensation under the sink between the two bowls.

If this is the dishwasher, why is that the only place there is condensation?

Thanks for your help.

*I thought I should mention that the dishwasher is about 21 years old.
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Old 09-17-08, 07:36 PM
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Are you using the heated dry function on the dishwasher? All dishwashers have an internal fan that blows air through the machine to dry the dishes. Some dishwashers vent this air through a vent on the door and some through a vent on the back of the machine. It is possible that if your cast iron sink is relatively cold and the dishwasher is venting into the under sink area that this is the cause of the problem.
Old 09-17-08, 07:57 PM
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Thanks for your reply. The sink is stainless steel.

We had another guy out today to look at it, but he is stumped too. He said he's never seen anything like this. The only thing he could suggest is that maybe the vent above the sink is blowing cold air directly on it and causing condensation. We have been here for 4 years and have never had this happen, so I am not sure if that is the cause.

Maybe we should start charging admission to see the possessed sink! Both people we've had look at it didn't charge us a service call because they couldn't explain what was going on.

I used the sink last night, then didn't use it again until late this morning. It was bone dry when I got up. I ran the dishwasher first. No condensation or moisture underneath the sink.

Then I ran cold water for a long time in the left side of the sink. Then I ran hot water. Nothing.

I repeated with the right side. It felt like there was more moisture on the right side, but there was never any condensation.

I had my son stand and spray the vegetable sprayer for about 10 minutes. No leaks or condensation. The sprayer sticks in the "on" position though. A huge nuisance if you cut the water on and it gets you.

I don't know what is going on, but now I am wondering what I am going to do about the smell coming from under my kitchen cabinet. We may have to sand the top layer of particle board. Oh joy!
Old 09-17-08, 08:22 PM
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I have a few questions.

What type of dishwasher is it? Installed or portable?
Is there any sound deadening on the sink bottom?
Are you sure the problem is condensation, and not some kind of leak?
A small pinhole leak can spray upwards making it look like condensation.

What is the temperature range at your home right now? How has the humidity been?
Are you on a well? Is your well water extremely cold?
Do you know if the dishwasher is actually using hot water? Maybe something is wrong.

Do you have the cabinet doors open or closed when the phenomenon occurs?

Is your home centrally AIR CONDITIONED?
Have you noticed you hot water being extremely hot lately.

Oh, and I almost forgot the most important question, Do you have any pink elephants?

Get me as much of the above info to I can keep trying to figure this out.

If possible, could you upload a picture of under your sink to a sit like and post the link to the photo here. Maybe I can see something you may have missed. More than 1 photo from different angles would help. And please add a pic. of the pink elephant, thanks mark
Old 09-18-08, 05:53 AM
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Hi Mark. I am going to put the answers to your questions below. Thanks for trying to help! I have tried using photobucket before, but have been unsuccessful. Maybe I am just a putz when it comes to computers.

Here goes:

1) It is an installed dishwasher.
2) I don't think there may be some sound deadening on the sink bottom. Is it a black coating? If so, there is some on each side.
3) I am not positive that it is condensation. One of the guys said it, so I just ran with it. It does look like that. About a pinhole.....can stainless steel sinks get them? The guy who used the word condensation ran his flashlight over the top of the sink looking for one. I am guessing a pinhole would be undetectable to the naked eye.
4) The temperature in my home stays at 70 degrees all of the time. I live in the south, so the humidity is high. It's almost always high!
5) We are not on a well.
6) Yes, I know for a fact as of yesterday that the dishwasher is actually using hot water.
7) The cabinet doors stay closed all of the time.
8) Our home IS centrally air conditioned.
9) No, I haven't noticed our hot water being extremely hot or any hotter than normal.
10) Yes, I have a pink elephant. She sleeps next to our green giraffe.

*I am pasting here some info from my first attempt at getting help with this problem. Could this have anything to do with it?

Here is one other piece of information I discovered after I posted: Every night after I am done with the dishes, I lay my dish rag on the part that divides the two sides of the sink. Tonight I noticed that the rag was soaking wet after I knew that I wrung it out completely. I am thinking maybe the faucet (which I in OCD fashion line up directly above the rag ) has been leaking some and then the saturated rag is somehow causing condensation under the sink on that middle section that lines up perfectly with where the rag lays. Does that sound plausible?

Thanks again for your help.
Old 09-18-08, 12:44 PM
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I need more info if possible.
Do the pink elephant and the green giraffe both eat the same food?
Maybe... the pink elephant had it's snout under the sink and sneezed

Seriously now,

Have you tried drying everything with a towel under the sink? It is possible to get a pinhole in the SS sink. I would put the stoppers in the sink/sinks and fill them up as high as possible. With a bright flashlight, look for any leaks or moisture while filling, leave full for a while, 1/2 hour, then watch while emptying.
Keep on eye on the bottom of the sink where the sink is connected for any leaks or moisture.

It does not sound to me that you should have a condensation problem, unless you have extreme differences in the hot and cold temperatures between the water and the air. I would keep looking for some kind of leak. It is hard to tell without me being there. I am still thinking. If I come up with more I will post it.

If you find more info to help or find the answer please post here.
Is your A/C a window unit or central?

**** I Just Re-Read some of your post****

If you had a cold water leak coming from the base of the faucet and you have nice Ccoollldd water coming from you well. It is possible that if the water was a constant leak soaking the towel between the sinks, throughout the night, you could cause a condensation effect on the bottom of your sink.
To test this, take away the towel and look for a leaky base and leave the towel off the sink overnight.

Last edited by plumbingods; 09-18-08 at 12:52 PM. Reason: additional info
Old 09-22-08, 03:19 PM
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We have central air. We are going to try your sink test tonight. This is the first chance we've had to do it.

Thanks so much for your help.
Old 10-19-11, 02:31 PM
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I have the same problem.

I have condensation almost identical to the above post...
#1-but I have cats instead of elephants.
#2- we are OCD but not with the towell on the sink.
#3-We have noticed the water getting hot FASTER than usual.
#4-We have changed faucet and lines and still have condensation.

I really need help, as my wife makes me feel like I am not solving this as fast as I should.
I have checked for other leaks under and around dishwasher.

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