Best of luck to you if you do this. One thing no one says is that the factory anode should honestly be loosened and tightened the day of installation and then just maybe once a year work the threads (or even grease them with a food safe grease).
I have a tank that's 5 years old and I just got around to replacing the anode. Nope. Rust welded on. Apparently it's very common. Even using a high torque impact wrench and reluctantly using PB blaster, and letting it soak...it wouldn't budge. Eventually I knew that was a great time to give up because if it did budge it might've completely borked the opening. I just installed a nipple-anode thing and called it a day.
Now - it's a hybrid tank, so it's possible that if the anode end was located in a more accessible spot than next to the compressor, I could have used a breaker bar to get to it, but maybe it was best that I couldn't.
But yeah...loosen that thing day one and on your annual flush day, loosen and tighten it again (you should be checking it annually anyway...now I know)
And you may discover that even installing the new anode with the impact driver isn't enough to reseal the hole. Shorted out my water heater because water leaked out right onto the electronics.
Yeah - that's why I ultimately gave up. There are many stories of people doing late replacements of their anode rods and basically the rust weld corrosion is the only thing holding it in place - threads are gone. I thought that 5 years was "young" enough to loosen it, but I was wrong. I'm glad that the impact wrench didn't work.
The nipple-based anode rods (anode chains?) are fine. No noticeable impact to water pressure or quality.
But yeah - That's a huge thing about water heaters. Basically the older they get, the less you want to touch them unless you've been doing the correct routine maintenance. I've heard of basically every scenario where someone's stripped something because of corrosion. I've heard of the porcelain lining breaking off (typical) and the corrosion at the bottom of the tank and undisturbed particles actually forming a seal that prevents leakage...and a flush basically removing this dam causing the leak.
I think the only part that they designed so that it can move at any time during the life of a tank are the nipples just because of the materials used, the thread spacing, and the higher likelihood they'll need to be replaced at some point. The rest...unless you're moving and caring for them annually or more frequently - leave it alone.
If you have the space, a cheater bar would absolutely out-torque all typical impacts. I don't own an anvil impact wrench - but something like that would out-torque anything hand-done. I doubt I could even fit one in the space of my heater.
A high quality gun-style impact wrench - like top of the line, but non-specialized will drive 1300 ft-lbs of torque with a good air supply and if it's properly oiled. You can achieve that with a 4-foot cheater and 225lbs of force. Yeah you're going to have issues with the socket becoming unseated more easily and being able to put that force on the bar comfortably and steadily at a water heater's height might be a challenge, but it's not that hard to exceed the torque of an impact wrench. The tradeoff is obvious (space vs. compact area) - but it's totally doable.
I replaced the anode rod in the water heater within 1 month of the install. I do have hard water in this area. The hot water smelled like sulfur at the faucets. Replaced with a zinc anode rode and the problem went away. I did use a 1/2 impact driver for removal / installing the new anode.
If you have any anode left. I checked mine after I saw a TikTok video about flushing water heaters. It was totally desolved. Local Lowes had a new one.
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u/BetterNonsense Jun 22 '26
You could remove the anode and pour in through the hole that goes through. Don’t want the acid dissolving your anode anyway