Thanks, I am interested to shut off the water heater when AC power is on. I see the pop out breaker, just wondering why the water heater would continuously on unless needed. I guess I have to install an on/off toggle.On my boat it is a pop out circuit breaker located near the AC power switch. It is white and doesn't look anything like the DC panel on off switches. Look in the AC area of your power panel.
Just push it in and it will pop out, you can turn it off and on with the circuit breaker. I only turn mine on foa 30 mim or so in the AM or during dinner to wash dishes with. We use the dock side showers when plugged into shore power.