A while ago I chased this down when someone asked what their "AESS" was. Turns out that Intellitec has an automatic module https://www.amazon.com/Intellitec-00...=1&*entries*=0
that manages an issue like this. In fact, there is an electrical code requirement that you cannot install more than 5 breakers on a 30 amp panel if there are two or more thermostatically controlled loads (A/C, H/W, reefer) without one. This unit will automatically shed a load (your electric hot water heater) when something else (microwave?) cycles up and shares the same 20 amp breaker. If it has more that 5 breakers on a 30 amp panel, A/C, electric HW and residential reefer...and was made after 2012, it should have one.