Is this much rust really typical of a 9yo AO Smith WH?

Discussion in 'Water Heater Forum, Tanks' started by avocent, Nov 14, 2013.

  1. avocent

    avocent New Member

    Messages:
    7
    I guess I was expecting more from my AO Smith <9 yo water heater. The WH was checked twice a year (on a well) for sediment, usually very very little. Anyway, is this really normal? I was expecting at least 12 years from the WH... will be replacing ASAP.

    Attached Files:

  2. Dana

    Dana In the trades

    Messages:
    2,785
    Location:
    01609
    Is the thing actually leaking, or is it just a bad paint job? In a humid basement, particularly in salt-air coastal areas it doesn't take much to get paint to fail. Replacing it just for some rust on the jacket seems silly- wire-brushing it out and daubing on auto-body rust-inhibitors would probably be enough to halt the spread of rust under the bubbling paint.
  3. avocent

    avocent New Member

    Messages:
    7
    Installed in a Colorado basement, very dry climate. Also - there is a very small hole on the side of the wh but closer to the top. The hole is 1/8" and if I appply pressure around the hole, a drop of water will weep out. So... there are no visual indicators of a leak overall (i.e. nothing actively dripping). Could the corrosion be caused by condensation forming between the metal skin and water tank, trapped by the insulation and hence causing corrosion of the skin?

    Or at 9yo, should I start over?
  4. Reach4

    Reach4 Active Member

    Messages:
    1,893
    Location:
    IL
    Go ahead and replace it, but pull the anode rod out for inspection. I expect you will find it to be eaten away. Replacing it before it was eaten away may have made the water heater last longer.

    To remove the rod, you will probably need a 6-point 1-1/16" impact socket and a strong impact wrench. They are installed much much tighter than they need to be. Some think the makers want to discourage changing the anode. They are said to be easier to remove when new, but who does that? Maybe you will to apply teflon tape to help make it easier to remove 3 years from now.

    If you replace a rod later, you don't need nearly that much torque... I am thinking 15 ft-lb would be plenty-- probably even that is more than needed. I would use teflon tape to put in a new rod.

    I went to a powered anode when I replaced my corroded-away anode rod. I am surprised that those are not discussed more often, but they are surprisingly expensive at $245 with shipping. I went that route to deal with well water sulfur. Had I put my big backwash filter in before changing the anode, maybe I would have gotten a zinc anode instead. However at this point, even with the filter, I am not sure which way I would go. Personally I would avoid an aluminum anode, but I guess I don't normally drink or cook with hot water. $245 is cheap compared to an installed water heater, and would I really be proactive enough to change my zinc anode out every few years?

    You might want to add a whole-house sediment filter too. I like the 20x4.5 inch Big Blue housings, unless you decide to go bigger. Smaller filters don't cost that much less, and they don't have as much capacity.
    Last edited: Nov 14, 2013
  5. Dana

    Dana In the trades

    Messages:
    2,785
    Location:
    01609
    There is no such thing as condensation inside the jacket of a warm water heater unless it's leaking, time to start over.

    Nine years is on the young side, but not unheard of. Total water volume moved through the thing and the acidity & oxygenation of the water can take out some sacrificial anodes quicker than others. If it had a 12 year warranty you should be able to get something back from the manufacturer- exactly what depends on the terms. You should be able to figure out what is/isn't covered for your model by looking at the warranty documentation on their website. (The serial number would be enough tell when it was manufactured, if you don't have sufficient documentation to determine when it was installed.)
  6. avocent

    avocent New Member

    Messages:
    7
    Thanks for the information. I will replace the WH and take pictures of the anode and post, if possible. I have a big blue hole house filter installed. The WH was manufactured Jan 2005 and installed April 2005. The warranty was 6 years so may be 9 years isn't that pathetic.

    Thanks.
    Last edited by a moderator: Nov 14, 2013
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,809
    Location:
    New England
    Usage and local water quality coupled with luck of the draw from the particular day it was manufactured are the bigger determinants of how long a WH lasts. The type and quantity of anode can make a difference in how long it lasts, but it's a lot less impact than the variables of how it actually made it through the factory.
  8. Caduceus

    Caduceus Master Plumber

    Messages:
    99
    Location:
    Pittsburgh, PA
    It appears that there is some exterior atmospheric corrosion. The 3/4" 45 fitting was soldered on and the heat may have affected the paint on the tank's jacket allowing moisture to prematurely attack the metal underneath. If the little green spots of oxidation fade as the pipe runs up and away from the fitting, that's a typical sign of spatter from the flux that was used to solder the fitting and wasn't wiped off.
    It's always a good idea, as stated above, to change the anode every few years, especially if a water softener is on the system. I know that you stated a filter, not a softener. I just added that info for general purposes.
    The water that you get from the little hole at the top of the heater should not be there and is an indication of a leak. That may explain the rust ring around the escutcheon for the drain in the photo.
    When a new tank is installed, try to keep the drip tube from touching the side of the tank like it is now. Sometimes the little details help out in the long run for preserving the life of the tank.
  9. avocent

    avocent New Member

    Messages:
    7
    Replaced the AO Smith with a GE/Rheem, same size, capacity. Install was easy. Double checked all the fittings (used Sharkbite WH fittings for the first time) and venting. Filled tank, turned on pilot, held for 1 minute, released and the pilot would not remain lit. Tried again (1+ minute) and again (2 plus minute) and still the pilot would not remain on. So pulled the burner assembly (4 TORX screws), examined the thermocouple/pilot relationship, all seemed correctly spaced. Reinstalled burner assembly, still the pilot would not remain lit. Goggled the symptoms (check thermocouple)... then detached the thermocouple from the gas valve, attached multimeter, turned on pilot (held down) and voltage did not climb (as expected). Back to HD, purchased $12 thermocouple. Installed in 10 minutes, fired up pilot and.. pilot remained on. Burner cycles correctly and no issues over 36 hour period. New WH, go figure.

    Attached Files:

    Last edited by a moderator: Nov 21, 2013
  10. Dana

    Dana In the trades

    Messages:
    2,785
    Location:
    01609
    Clearly write the date of installation on the side of the water heater in permanent marker "just in case"...
  11. avocent

    avocent New Member

    Messages:
    7
    copy, good point
  12. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,253
    Location:
    Cave Creek, Arizona
    quote; I will replace the WH and take pictures of the anode and post, if possible.

    If it did its job, then it was "gone" within the first few months or couple of years, but I have only replaced a couple of them in my 60+ years, (and NEVER in any of my own water heaters), since their main benefits are when the heater is new.
  13. kcodyjr

    kcodyjr New Member

    Messages:
    103
    Location:
    Chelmsford, MA
    hj, could I prevail upon you for an education? Why is their main benefit when it's new; does galvanic corrosion somehow stop after awhile?
Similar Threads: much rust
Forum Title Date
Water Heater Forum, Tanks Not much hot water, and flushing the tank produces clear, cold water Mar 4, 2013
Water Heater Forum, Tanks how much gas per year did this water heater use????? Mar 7, 2011
Water Heater Forum, Tanks Indirect Water Heaters - what's the most reliable brand? And how much for install? Aug 12, 2010
Water Heater Forum, Tanks Rust in water tank Jan 7, 2014
Water Heater Forum, Tanks Parent's Water Heater Valve Leak Causing Rust Mar 10, 2013

Share This Page