Reliance 606--3 years old.

Breaker trips immediately after re-setting--sometimes with a big spark in the breaker box.

Wiring in breaker box and in HW tank all looks good.

Replaced G.E. double 20 amp breaker. New breaker still trips. Problem not solved.

Customer says that the tank was working fine before breaker started to trip. The water was the same temp as always.

The bottom element appears to be very corroded. Is it possible that a bad heating element or thermostat could trip the breaker like this?