I am working with the Rheem API to get my ac into Vera and making very good progress. Once I have the ac solid I may look into the water heater depending on interest. As they share the same API I wrote the code such that I could add the WH down the road. I do not currently have the Econet WH, so for me to develop the code I would need someone to temporarily give me access to their account as the API documentation is non existent. The only way I can develop the code is to test each get and post statement.
In any case, this is just a poll to gauge interest. Shoot me a PM or reply here.