Water heater leaking or noisy

Noises tell you a lot. Popping or rumbling usually means sediment on the bottom of the tank, and the fix is a flush. The videos here sort normal sounds from problems, and show replacing an anode rod that has corroded away, which extends the life of the tank.

Leaks are different. A leak from a fitting or the relief valve can be repaired. Water pooling under the tank, or rust at the base, usually means the tank has failed and needs replacing. Shut off the power or gas and the cold water supply, then call a plumber. Gas heaters, flue problems and relief valves that discharge are safety issues; read when to call a licensed pro.