240v Z-Wave Switch

My idea is brilliant! Although, after researching the possibilities, I can’t take credit for the idea.

I am brainstorming the possibilities of adding the on/off capabilities to two 50g electric hot water heaters. I imagine they are both 240V and for what its worth, they are plumbed together (cold water into one heater feeds the second heater and out to plumbing fixtures). Can you imagine the power savings if these were turned off during the work day and turned on 30 minutes before returning home…OR…turning them off during the late nights…OR…while traveling during the weekends

My research is encouraging an Elk 9200 Relay Contactor and includes the following links:

Do you have any experience with 240v Z-Wave? If so, what do you recommend…and do you sell such a thing? I wonder if the amps come into play --J

I don’t have any experience switching 24VAC with z-wave but the Elk 9200 combined with a z-wave appliance module should work just fine based on the specs as long as your water heaters draw less than 60 amps.


You might also consider a home energy meter to measure the energy savings.

So it is possible that I would need two of the Elk 9200’s…one for each water heater, depending on the amp. The 2Gig on/off switch would control two Elk 9200, with a splitter/multi-plug, wouldn’t it?

I just read the energy meter thread a few minutes ago…putting it on the “want list”

That is correct, the appliance module should be able to control both.