water heater anode rod replacement

[darkoshi]

With Q's help, I finally got around to replacing my water heater's anode rod this July.

"Water Heater Anode Rod" (Watch on YouTube)

The old anode rod that I removed was about 2 feet long. Based on the diameter of the old rod, I think it was still in pretty good condition and probably could have lasted some more years. The build-up of white stuff (oxidation) on the rod could be normal, but I'm not sure. Maybe having that much build-up prevents the rod from working as well as it should.

I don't normally drink or cook with water from the hot water tap, and I think this is a compelling reason not to do so. A lot of that powdery build-up likely ends up in the hot water that flows out of the tank, and that's not something I would want to ingest.

This is how the rod looked after removing it from the tank, while it was still moist:





This is how the rod looked after having dried off:






Previous related video


Warning: The following notes are intended for informational purposes only.
They are not meant to be a complete or definitive guide on how to replace an anode rod in anyone else's water heater. Don't try to replace an anode rod unless you are confident in your own abilities and have done the necessary research.
I assume no liability for any damage that may result from anyone's use of this information.


Steps on how I replaced my gas water heater's anode rod:

• I verified I was able to access the house's main water supply valve by the street (in case something went wrong and I had to turn it off quickly).


• I checked the various shut off valves in the basement and house, to make sure they worked.


• I noted down the original temperature setting on the water heater, so that when done, I could set it back to the same temperature.


• I turned the water heater's thermostat to the lowest position, and then turned off the gas supply.


• I flushed sediment out of the water heater:
  
  Flushing the tank is not a necessary step for replacing the anode, but I decided to do it at the same time. In retrospect, I should have flushed the tank after replacing the rod rather than before, as some junk likely got knocked off the old rod during the process of removing it. If I had used vinegar to clean the threads after removing the old rod, that would have been another reason to want to flush the tank afterwards.
  
  
  
  • left cold water inlet supply to water heater turned on
  
  
  • attached hose (using teflon tape on threads) to the water heater drain valve
  
  
  • opened the drain valve all the way so water would come out with high pressure.
  
  
  • I let the water run out through the hose for about 20 minutes until it looked mostly clear.
  
  
  • closed drain valve, but left hose attached
  
  


• I drained some water from the water heater, so that it wasn't completely full. (I read that this should be done, but I think the tank should be left fairly full to give it weight, so it won't be as likely to turn when the old anode rod is being loosened.)
  
  
  
  • turned off cold water inlet to water heater
  
  
  • opened hot water valves in house; verified that the water was really off. Kept the valves open.
  
  
  • opened drain valve on water heater and let some water drain out thru the hose which was still connected
  
  
  • closed drain valve
  
  


• Anode rod replacement:
  
  
  
  • cold water inlet to water heater was still turned off.
  
  
  • hot water valves in the house sinks were still turned open.
  
  
  • popped out the small round plastic piece on the top of the water heater, which covers the anode rod.
  
  
  • removed the old anode rod
    
    • first we tried using a manual socket wrench, while one person held the tank steady to keep it from turning. But it didn't come loose easily, so we switched to using the impact wrench.
    
    
    • used impact wrench in reverse direction (counter-clockwise), to loosen the old anode rod.
    
    
    • I did not end up needing to use the universal joint
    
    
  
  
  • I pulled the old rod out. It was much shorter than I expected - about 2 feet long. It was crusted in white stuff.
  
  
  • I cut one link off of the flexible new rod I had bought, to make it shorter and closer in length to the old one.
  
  
  • On the new rod, I wrapped the threads with 5 turns of teflon tape.
    (it will screw in clockwise, so teflon tape should be put on counter clockwise when looking from top)
  
  
  • We screwed in the new rod. This was the most difficult step, as the threads didn't catch well at first. Several times, the rod seemed like it was screwing in okay, but then it was still totally loose.
    The tank threads were filled with the same white stuff as was on the old anode rod; that was probably making it harder to screw the new rod in. In retrospect, I could have used an old toothbrush or a small wire brush, along with vinegar, to first brush the threads clean.
  
  
  • We tightened the new rod using the manual wrench, with one person hugging the tank to keep it steady.
  
  


• opened cold water inlet to water heater to fill the tank back up. (kept faucets in house turned open)


• shortly opened the pressure relief valve, and let a small amount of air/water out through there. (at this point, all the water in the tank was cold, so there was no danger of the water burning us.)


• verified there was no water leakage from around the anode rod, nor from cold water inlet


• let the water run for a while with the taps in house open, then closed the taps.


• turned the gas supply to the water heater back on, and re-lit the pilot flame.


• again verified there was no water leakage anywhere.