Rusted anode nut

One thing to consider. if it's that corroded it probably no longer has a sacrificial anode on it and is slowly destroying the tank.

I would at least buy some penetrating oil and spray it over a week or so while letting it heat up and cool down. Then after a week or so see if it has become looser.

Thanks for all the responses! Since the water heater is working OK (for now), I'm not going to risk tearing the threads up. :B

25% acetone, 25% ATF, and 50% mineral spirits is what I use as a version of "Ed's Red" bore cleaner. I always have at least a pint of it around for gun cleaning. I've found it to be an excellent penetrating oil. I'm not surprised to read what was mentioned above about the acetone/ATF mix.

That said, I wouldn't want to use anything like this that's going to creep past the threads into a potable water system.

I'd just leave the anode in place and forget about it.

If it really started grating on me, I'd buff off the loose rust on the outside with a wire wheel. Then I'd warm it up a bit with a propane torch and dab an old candle around the threads. The melted wax will draw into the threads. Then tighten it a bit before trying to back it out.

The rust on the outside is no indication of what's going on inside the heater. It is simply water seeping past the threads and causing the plug to rust. The anode itself is only going to corrode to protect the shell where there may be holidays (pits) in the internal coating.

If you ever pull an anode out and it looks like new that means it wasn't doing anything for you. Either there are no holidays in the tank lining or it was electrically insulated from the shell because someone used too much thread sealant when installing it.

GoPackGo wrote:
Acetone and atf may work as you describe but PB Blaster has always worked for me. And it's all in one aerosol can. I choose not to breathe acetone if I can avoid it.

And PB Blaster is easier to carry around

Acetone and atf may work as you describe but PB Blaster has always worked for me. And it's all in one aerosol can. I choose not to breathe acetone if I can avoid it.

Old-Biscuit wrote:

Might not work due to plug with anode on it is the threaded part which should heat up and then when you spray with cold air the bung area that plug is screwed into will probably cool off first and contract.

I've removed several anodes and more than a few nuts and bolts using the method I described. It works unless the tank has gone years without the anode being removed and rusted beyond repair.
Heating up the tank/water and then hitting the anode with compressed air causes a difference in temp between the anode nut and the tank. Simple high school physics. Heat expands and cold contracts. Any mechanic or farm boy will have learned that.

GoPackGo wrote:
x2 on what Darsben said. PB Blaster is amazing stuff.

Disagree, the best penatrent oil is a 50/50 mix of Acetone and ATF. Sounds strange but it was in a machinist magazine years ago. In their testing they found that a rusted on nut/bolt would take roughly 350 lbs of force to remove. With the 50/50 mix of acetone and ATF it took 50 Lbs, I think PBblaster still took some 200lbs of force.

Wadcutter wrote:
Put down the long handle breaker bar.
Several days soaking with PB Blaster. WD40 isn't penetrating oil. After a few days soaking fill the water heater and turn it on so the water gets hot. It will heat to about 115*. After a couple of hours of the water heating then spray the nut with compressed air like for computer parts. The air will be cold. The heat of the threads and the cold nut will usually break free.

Tank will get to at least 130*F during heat cycle (T-stat pre-set for 130*F) which should only take 30 minutes or so.

Might not work due to plug with anode on it is the threaded part which should heat up and then when you spray with cold air the bung area that plug is screwed into will probably cool off first and contract.

Spray it with PB Blaster or Liquid Wrench for a few days and a light occasional tap on end of plug should loosen the rust.

Before you regret what you are doing. Spend a week spraying it twice a day with something that breaks up rust. After a week of it soaking,it will probably come loose without you tearing anything else up

darsben wrote:

Wadcutter wrote:
Put down the long handle breaker bar.
Several days soaking with PB Blaster. WD40 isn't penetrating oil. After a few days soaking fill the water heater and turn it on so the water gets hot. It will heat to about 115*. After a couple of hours of the water heating then spray the nut with compressed air like for computer parts. The air will be cold. The heat of the threads and the cold nut will usually break free.

Oh wow what a great idea

Broke free a lot of frozen nuts and bolts using a similar process over quite a few years of bending wrenches and busting knuckles.