I had to buy a 1 1/16" socket as well as a 3/8" to 1/2" drive adapter because my wrench is 3/8 and they don't make bigger sockets like that for 3/8 drive (probably for a good reason).

Anyway heater is only like 5 years old but this is the first time removing the anode and it was stuck pretty good. My socket extends out to about a foot, but that wasn't enough for the leverage I needed. I didn't have a metal pipe to use as a cheater so I grabbed an old razor scooter that was bound for the trash and pulled the handlebar tube out of it. Slipped that guy over the handle of the wrench to give it a few more inches of length and finally was able to get it loose. Turns out the anode is barely eaten at all. Maybe 3 inches of it a little near the top. The rest looked good. Put it back in with some teflon tape and good for another year. Through away the scooter but kept the tube for later.