pasadena_commut
Well-Known Member
I replaced the anode on our American Water Heaters tank with a KA90 purchased directly from the manufacturer in 2011. In 2016 it was pulled out and inspected and 95% of it was still present. Both times it was a pain to remove and I had to use an impact to break it free. The second time it was really hard to make it stop leaking. I tried a bunch of things, like varying amounts of tape, and cleaning the tank threads with a brass toothbrush and some vinegar. Eventually it sealed after thread cleaning, teflon taping, and then tightening down hard. That was not with the impact, but by hand. ("Hard" being relative, I am pretty skinny so what feels like a lot of force to me might not seem like much to a bigger guy.) Both times I verified that there was electrical connectivity between the nut on the anode and the steel of the tank. Also, to the extent I could see the threads in the tank, they didn't look chewed up, but it wasn't shiny metal, so probably some rust.
Time to replace this rod again. I want to do a better job of cleaning up the tank threads this time, because I suspect the sealing problems were due to some chunks of rust that were still present on those threads. I have seen videos which suggest using a 3/4" NPT tap, and others which suggest that working a 3/4" nipple in and out is sufficient. Is one of these better than the other, or is there something in between that is better than those extremes? I'm afraid that the tap might cut new threads, and the nipple is continuous thread, so it doesn't really have a way to work rust out, other than maybe by driving it down the spiral and into the tank.
(Yes, I did ask in another thread about ways of getting vinegar into the tank without taking out the anode. I neglected to check my notes first, so I didn't see that this maintenance was now due.)
Time to replace this rod again. I want to do a better job of cleaning up the tank threads this time, because I suspect the sealing problems were due to some chunks of rust that were still present on those threads. I have seen videos which suggest using a 3/4" NPT tap, and others which suggest that working a 3/4" nipple in and out is sufficient. Is one of these better than the other, or is there something in between that is better than those extremes? I'm afraid that the tap might cut new threads, and the nipple is continuous thread, so it doesn't really have a way to work rust out, other than maybe by driving it down the spiral and into the tank.
(Yes, I did ask in another thread about ways of getting vinegar into the tank without taking out the anode. I neglected to check my notes first, so I didn't see that this maintenance was now due.)