Really slow leak under hot water heater

Discussion in 'Water Heater Forum, Tanks' started by murphysf, Oct 16, 2020.

  1. murphysf

    murphysf New Member

    Joined:
    Feb 25, 2018
    Location:
    SF Bay Area
    Hello

    I have a American Hot Water Heater, it is just slightly over 6 years old, just past the warranty.

    It is a natural gas, freestanding 40 gallon hotwater heater

    Model Number
    UG6140T403N

    I flushed it about 4 months ago and all kinds of sediment came out. I was surprised as in the SF bay are we have some of the best "softest" water from Hetch Hetchy.

    Today I noticed a small puddle of water and water path down my garage floor.

    it is leaking from the bottom.

    I put my finger in through the sheet metal hole where the drain valve screws in and noticed that the insulation is wet. Perhaps the water is wicking up the insulation or the leak is running down between the tank itself and the outer metal housing.

    I got a towel and dried everything up however minutes latter very small seepage. I noticed that the water temp of the water that is seeping is at around room temp or even colder.

    I always assumed that the bottoms of the tanks corroded and that is where the leaks originate.


    Perhaps it is leaking at the top inlet side? and running down the side of the tank?

    Ideas?

    Thanks!
     

    Attached Files:

  2. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    Make sure the leak is not water coming out of the temperature and pressure relief valve. If the water is not coming from the T&P, I expect you need to replace the WH.
     
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  4. murphysf

    murphysf New Member

    Joined:
    Feb 25, 2018
    Location:
    SF Bay Area
    I'll take a closer look. I'm not currently at the location but will check it in the morning.

    After I first posted yes after I posted I thought about the cold inlet nipple.

    If there is a small leak could it run down the side of the tank behind the metal housing so it wouldn't be visible?

    I'll take a closer look at the top.
     
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    Water will take the path of least resistance, and it could be a circuitous route! Unless you're lucky and it's a nipple or pipe above, sounds like you need a new WH. THey can sometimes leak slowly for a long time, but sometimes, it quickly gets out of hand and becomes a torrent. Don't delay figuring out what's going on, and repair or replace as needed. Being in the garage, it might not create a lot of damage if it blows, but only you would know that for sure. If it happened while you were away, it could waste a lot of water, though.
     
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  6. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    You could tie a cotton cord or tissue around the nipple to see if that gets wet.

    I expect that to not be corrosive.

    I haven't seen anybody say repairing a leak in a WH was successful. I am not a pro.

    You could take a look at the anode, if you are curious as you are removing the old WH. If the WH has a 1-1/16 hex head on top, then you would use an impact wrench to remove the anode for inspection. If no hex head, the anode would be under the hot nipple. Anyway, if it is eaten away, you might want to be the rare person who changes anodes on a WH with your new WH.
     
    Last edited: Oct 17, 2020
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  7. WorthFlorida

    WorthFlorida The wife is still training me.

    Joined:
    Oct 28, 2009
    Occupation:
    Retired
    Location:
    Orlando, Florida
    The weakest point for a water heater for corrosion is at the welds. A flat sheet of steel is rolled into a tank and the seam is welded. The top and bottom are welded. For a gas unit a pipe is welded through the center for gas exhaust with a flue baffle. Holes are drilled for the fittings for water, T&P and for a drain valve. Then the inside of the tank is coated with a porcelain power then baked in an oven to to change to powder to glass, (AKA glass lined). If a weld of any length is not perfect and contains any contaminants, the porcelain may not have fully coated the weld or it is too thin. Over time the steel could rust through. With a gas WH there is the internal flue, therefore a gas WH has a lot of welding.

    Your water heater meets the latest energy standards mandated by the EPA and the foam now used between the water tank and the other jacket is extremely dense. If the leak is from the top, as Jim stated, the water will travel to anywhere. If other than the T&P or a threaded fitting at the water heater, the tank needs to be replaced. The T&P valve can weep water when the cold water temperature gets heated and expands where the pressure nears or exceeds 150 PSI. If you do need to change the WH, besure to install an expansion tank, now required by many municipalities and manufactures. The expansion tank will take the stress off the water heater (pressure) when the water expands from heating.

    This is doubtful that you are having condensation. I had a new home with a basement in Syracuse, NY. The water heater in the very damp basement from the new concrete and with extremely cold city water, I would get condensation above the gas burner on the tank. I could hear it turning to steam as the water was being heated. If I opened the burner access panel I could see a little water laying on the bottom. Cold water temp was around 47 degrees.

    [​IMG]
     
    Last edited: Oct 20, 2020
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  8. murphysf

    murphysf New Member

    Joined:
    Feb 25, 2018
    Location:
    SF Bay Area
    I ended up replace the water heater

    I put in a Bradford White URG140T6N, does anyone know what the difference is between the URG140 and URG240?

    Thanks
     
  9. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    Last edited: Oct 20, 2020
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