Returned and installed a new 80 gallon electric heater with a new pan, thermal expansion tank, and shutoff. Hauled away the old heater. Tested all water lines to ensure proper function and no leaks. Put an electrical tester on the elements to ensure power was going properly to the unit. When turning the water back on to the home, I noted when in incoming line to the heater was isolated, that water was trickling into the tank from the hot side. This could be due to a cross connection. Asked customer if they had experience any crossover issues and they haven’t. Made the customer aware of what I observed.