Today I saw an electric water heater that had wet insulation covering both the upper and lower thermostat controls. The water had been off for over a year, and it was turned on just for the inspection this morning. Only the bottom portion of the insulation on both upper and lower was wet. The "plumber" who I doubt had a license, that the realtor used to dewinterize the house said it was nothing to be concerned with. Water around electric controls. Just doesn't seem right to me. Need to get this written up, not sure if it's even something that needs or how to explain it. Has anyone else seen/heard of this?

If it was just turned on the moisture you saw was more than likley condensation but you should have seen rust also if it was off for a year. Your comment should be on it's performance first, and then address the fact that moisture was noted and further evaluation is required after the unit has had time to climatize. Around 2 or three days. If it's still wet after that then it is a leak.

I doubt it was condensation as condensation would not 'only be in that one area'.

More likely a leak, either from above (a fitting at the top of the tank) or from the element(s)

If the water has been off, and the water heater drained (to winterize it), then de-winterizing it would mean the water heater be re-filled before turning the power to the elements back on, otherwise the top element would burn out.

I suspect the water may have been from a leaking T&P valve. When you drain a water heater, open the T&P and allow air to enter the tank to replace the water draining out, when re-filling the tank, open the T&P to allow that air out and to allow the water in without creating back-pressure compressing the air. If the T&P leaks when opened (which is when most leak) and the T&P would have been opened quite a while allowing air out, at some point water will come out and leak if it leaks.

IF the plumber is not paying attention to the water heater filling, it may have filled and had water running out the T&P for a while, which could mean it was leaking for a while, before the plumber closed the T&P valve.

Did you test the T&P valve? If so, was it leaking?

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Jerry Peck, Construction / Litigation Consultant
Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
www.AskCodeMan.com

That's why I made the comment about the rust. Since you can only observe moisture in the fiberglass at the element access panels, rust coming through the exterior covering would indicate moisture in other areas that would confirm the condensation theory. I guess I didn't explain too well

You did explain it well, I was commenting on the statement that Kory made which was "Only the bottom portion of the insulation on both upper and lower was wet." and nothing about water or moisture or rust anywhere else.

Even if there were rust all over, I would doubt the condensation theory as, with the water off, the water heater drained for winterization, and no power on the elements, and with insulation on the inside the outer tank covering, what is to cause condensation, unless on the *outside* of the outer housing?

I may be missing something here, but condensation typically collects on the cooler surface, and the outer covering would be cooler on the outside of it. If any condensation were to occur inside the outer covering, I would think that would be on the metal tank itself, which would not show rust through the outer covering anyway.

Where is my thinking going wrong?

And if the tank was insulated with that foam and not fiberglass, I doubt there would be any condensation on the outside of the tank anyway. Any condensate would be on the inside of the tank, and that is intended to have water in it.

__________________
Jerry Peck, Construction / Litigation Consultant
Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
www.AskCodeMan.com

Jerry, yes I did test it and it did not appear to be leaking. I think you may have hit the nail on the head about it being opened when the "plumber" turned on the water. I was there when he did and never saw him go to the water heater until after he turned on the main water. I also remember thinking that it was unusually loud filling up at first then the sound went away (I was by my truck when he turned it on). Now that I think about it, it got quieter when he was walking away. I recommended that they have it serviced just to make sure nothing was wrong.

Thanks!