I installed solar in our house recently, then I bought 4 of these:
Modular Contactor 25 A 230 Vac 2 No Co Jvc2 20 25 A and connected them with Ajax Wall Switches. Now I control 3 geysers and the swimming pool pump from my phone. Easy
Intallation was straight forward once you understand what all needs to be in the initial kit (element, thermostat pocket, kwikot flange). I opted to use a seperate compatible thermostat to connect the system to my existing CBI Geyser controller. From cold it heated up in about 2.5 hours and happpily runs through my inverter on solar during the day.