Anode Length - Old Vs New is Longer

Discussion in 'Water Heater Forum, Tanks' started by RayN, Dec 16, 2017.

  1. RayN

    RayN New Member

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    Houston, TX
    I am draining the water heater today. Its a Rheem 50 Gallon Gas Model 2250F1. It will be 5 years in March 2018 and I have never drained it. I finally got it to drain, but that is another story.

    I have a replacement flex anode rod (https://www.homedepot.com/p/Rheem-P...ctric-and-Gas-Water-Heaters-SP8371B/205652259) which is 10 inch longer.

    The original was 44 inches solid and the new ones is flex 54". Each of the solid element is 12" long and there are 4 elements connected by a cable, so total 48" worth of magnesium. I think it will still fit as is, and I guess the lower portion will just lay in there at the bottom. Is that acceptable?

    Should I me cutting the bottom piece to account for 44" or should I leave its as is or cut to some other in between length? You input will be appreciated.
     
  2. Reach4

    Reach4 Well-Known Member

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    I would cut it to not touch the bottom. You could stick a tape measure down there, but I would think the original length would be good if that is 2 to 4 inches from the bottom. If the length of the original is much different, I would do some more research. I did not find an optimum length. I am sure touching the bottom is bad.
     
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  4. dj2

    dj2 In the Trades

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    "Rheem 50 Gallon Gas Model 2250F1".

    Is this the correct model number?
    Give us the model number as it's written on the unit.
     
  5. RayN

    RayN New Member

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    20171216_102229_1.jpg
     
    Last edited: Dec 16, 2017
  6. RayN

    RayN New Member

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    It looks like the bottom is 48" and the anode rod got eaten up the most in bottom 12 inches (its is bare rod in first 2") and top 12 inches. I will wait for experts to chime in. Looks like the anode is not supposed to make a contact with the tank, perhaps the top of the tank where is screws-in is isolated. Thanks... 20171216_111318.jpg
     
  7. LLigetfa

    LLigetfa DIYer, not in the trades

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    Not isolated. It makes electrical contact through the threads.
     
  8. RayN

    RayN New Member

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    So, do you think it is desirable to cut to right length or it do not matter if the bottom of new anode touches the water heater bottom?
     
  9. RayN

    RayN New Member

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    Ok, I decided to cut by 8", and put a date on the water heater, when the anode was replaced. I really need to change the drain to a full port ball valve drain, as it clogged on each drain and fill.
     
  10. Reach4

    Reach4 Well-Known Member

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    Do you have an electric pressure washer? Imagine spraying that into the anode hole.

    You could just put a 3/4 NPT nipple in place of the drain faucet in there temporarily for flushing purposes. You could use brass, and put your ball valve on it, or you could use steel temporarily for flushing only, and put the plastic valve back in place when done.

    It is OK to put PTFE tape on the anode threads. The threads will cut right through to make electrical connection. You don't have to torque it nearly as tight as it was originally. I think 15 ft-lb should be fine.
     
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  11. RayN

    RayN New Member

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  12. Reach4

    Reach4 Well-Known Member

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    FYI, Terry has pointed out that he can sometimes unplug the drain by opening the valve when the WH is pressurized.
     
  13. RayN

    RayN New Member

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    I bet it is true with full port valve. I end up connecting a washer hose to the end of garden house and back flushed from hose bib outside.
     
    Last edited: Dec 16, 2017
  14. LLigetfa

    LLigetfa DIYer, not in the trades

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    I'm pretty sure that is what @Terry endorses.
     
  15. MASTERPLUMB777

    MASTERPLUMB777 In the Trades

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    That is why you want ti install a full port ball valve,
    next time you are in the plumbing section pick up a hose bib and look inside see how small the hole is that the water runs though
     
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