Rheen Econet Water Heater

I have a Rheem Econet water heater that I used to be able to turn on (enable) and off (disable) via Wink. Since I have dumped Wink for Home Assistant, I have been diligently trying to move my devices to Home Assistant. Most, but not all of them work. Does anyone know how I can turn on and off my water heater via Home Assistant? I have it connected and I can see the water temp. When I try to move beyond in config I get the “This entity does not have a unique ID, therefore its settings cannot be managed from the UI.” message. Is there a way I can turn the water heater on and off? How can I edit YAML to do this?

I just used the standard Home Assistant instructions:

This only gave me status information but does not allow me to control the water heater.