Two to three times a year I bypass my water heater, drain the tank, and rinse out any sediment that build up. We full time in our RV so the water heater stays on all the time. This can cause a lot of sediment buildup in the tank.
My tank is steel so I also check the anode rod for excessive loss. The last inspection and cleaning I found the anode was close to needing replacement. I replaced the anode along with the P&T valve because it was weeping excessively.
I could also pull out the electric heating element but I replaced it with a new one last inspection.
Already have my next water heater inspection scheduled for early December