Control options for the ZigBee control module

Product Review: Remotely Controlling an Electric Water Heater with a Leviton Zigbee Module 20

One of my favorite features of my Ecobee WiFi thermostats is the ability to heat or cool a location so that it’s nice and comfortable by the time we walk in the door. For example, our furnace and heat pump at our cabin both use electricity, so I save money on my electric bill by allowing a very wide range of internal temperatures (50F – 90F ) when we’re not there, and only using electricity to heat or cool it right before before we arrive (to make it comfortable) and while we’re there (to keep it comfortable).

Recently, by combining one of Ecobee’s $25 add-on ZigBee Modules with a Leviton 73A00-3ZB wireless load control module ($230 retail, approx $200 street price), I was able to extend that energy savings and convenience to the cabin’s electric water heater.

The Ecobee ZigBee module is primarily designed to control Ecobee’s own branded Smart Plugs, but also enables the thermostat to control a wide number of other ZigBee home automation devices:

Ecobee's ZigBee module allows you to interface with other ZigBee home automation devices

Ecobee’s ZigBee module allows you to interface with other ZigBee home automation devices

The Leviton Wireless Load Control Module (which is sold by Leviton, but the labelling seems to imply that it’s built by the highly respected home automation experts at HAI) acts as a remote-controlled switch for power-hungry electric devices… such as a 240V electric water heater.

"Leviton" Wireless Load Control Module

“Leviton” Wireless Load Control Module

Wiring the control module to the water heater was pretty straightforward. First, I flipped the water heater’s breaker to kill power to the circuit, then disconnected the hot (black) and neutral (white) wires that ran through the metal flex-conduit from the wall and were wired to the to the water heater’s hot and neutral wires.

The control module has three wires: black (hot), white (neutral), and orange (switched load). So I connected black on the Leviton to black (hot) from the panel, joined all three neutrals together (panel, control module, and water heater), then wire-nutted the the orange wire from the Leviton to the water heater’s black wire. Had there been a junction box back on the wall, I probably would have wired the box there. But since the Romex ran straight from the wall and through the conduit, I did it this way.

Wiring the Leviton Control Module

Wiring the Leviton Control Module

I put back the protective panel and cleaned everything up with the conduit, then used sheet metal screws to mounted the Leviton box to the top of the water heater, and made sure there was a drip loop:

Hardware install done

Hardware install done

Adding the device to the local ZigBee network was easy. Similar to setup of a Bluetooth device, I set the Ecobee thermostat to “find” mode, then used a magnet to activate the Leviton and make it “visible” to the ZigBee network. It took about 30 seconds, and then it was “seen” by the thermostat.

When the ZigBee module is installed, a couple new icons appear on the thermostat, including one that says “Plugs.”

New "Plugs" icon on Ecobee

New “Plugs” icon on Ecobee

Pressing the Plugs icon revealed the ZigBee plugs that the thermostat could “see:”

Available ZigBee plugs

Available ZigBee plugs

Pressing the outlet icon (I named my plug “Laundry Water Heater” because I actually have two in this house), exposed the control options for the Leviton:

Control options for the ZigBee control module

Control options for the ZigBee control module

It’s clear I could get fancy with the schedule, but for this application, I just wanted the ability to be able to remotely turn the water heater on before arrival, so we’d have hot water when we walked in the door. The Ecobee interface allows great control from the thermostat itself, but that’s not this useful in my case. Remote control is available via the Ecobee website interface, but not available from their mobile app. That’s a big black eye for the Ecobee in my book. Any device that has an app and touts remote control abilities simply must have the ability to perform those remote control options via the app.

The Ecobee allows separate Wake, Home, Away, and Sleep scheduling for each ZigBee plug, which is a great feature. Were I using a setup like this in my primary residence, I’d probably configure a schedule for the water heater so that it doesn’t heat in the middle of the night, thereby saving more energy and money.

Another drawback with this setup is that it would be nice to be able to track power usage of the switched load (the water heater in this case) via the control module. At first, I thought it might be a compatibility problem between the Ecobee and the Leviton device, but with some more research I think I’ve concluded that the Leviton doesn’t report power usage. That’s a shame — that’s very useful info.

The bottom line is that for $25 you can turn your Ecobee into a basic ZigBee control unit (that’s a great deal) but that you have to spend $200 more for the Leviton unit if you want to control a 240V high amp device like a water heater. Controlling a 120V device (such as a lamp) is a lot cheaper, and I suspect that a good chunk of the high price for the Leviton piece is due to its need to support higher than standard loads.

The power is ridiculously cheap out at the cabin (2.5 cents per kw/hour) so it will take a while for this investment to pay off vs. just leaving the water heater on all the time. Although, there’s some admittedly additional value just for the geek points of being able to remotely turn on  your water heater so you can have a hot shower upon arrival. 🙂

The Leviton does exactly what it should do, and does it well. The $200 price tag seems a bit steep, but it doesn’t have much competition… so I supposed they get to control the price of admission for now. The Ecobee also performs its part in this setup reasonably well, but the absence of smartphone app control of the remote devices is a big red mark for me. If they fix that, I’ll come back and edit this post to give them full marks.

As always, I welcome your questions and comments below!


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  • Have you seen any savings with this setup? Any interesting tidbits or suggestions? I want to try this setup myself. Thanks!

    • Hi, Olin. Yes, I’ve seen savings, because this is a vacation house that sits empty most of the time, and not heating the water for weeks at a time will add up. Electricity out there is cheap, so it doesn’t add up fast, but it does add up and time is on my side. 🙂

  • Hey Steve, do you see other ways of remotely shutting on and off a 240V heater? Thanks!

    • Hi, Olin. I’m becoming more of a fan of the SmartThings Hub, and devices that work with it (this Leviton unit actually would, since the ST Hub supports Zigbee). I’ll keep an eye out for other devices that can handle larger electrical loads.

      • Thanks! Am poking around at existing load controllers for water heaters that could help us reduce the cost of deployment across a large number of units.

  • Steve,

    I have enjoyed pursuing your blog topics. I was wondering how you are handling this HW heater now with the Ecobee3. I have a weekend place (actually a houseboat) it does have a heatpump. I currently have just a cheap WiFi thermostat there. Nothing for the main house or water heaters at either place. As these are the two big users I would think that controlling these together makes sense.

    • Good question, Joe. I’m still using an older Ecobee Smart at my cabin just do I can still use the ZigBee stuff. Eventually, I’ll put a SmartThings hub in there, which will take over ZigBee control.

      • Nick

        Steve, thanks again for the valuable info. I bought a ST Hub and a Leviton 73A00-3ZB, but I can’t get the hub turn the switch on or off. ST tech asks me to reach out to you to get any info that I can use to get the two to talk to each other (particular profile or app). It does connect and they exchange data per the events list, but the switch will not go on or off. the supported zigbee types are:
        Zigbee dimmer
        Zigbee Hue bulb
        Zigbee switch

        None of which work to turn the switch on or off.

        I tried z-wave profiles with no success.Can you help?

      • Nick

        If this helps: I note that the Leviton switch 73A00-3ZB, according to Leviton’s website:
        “Utilizes ZigBee Pro Home Automation wireless profile”

        • I’ve just got mine set up as a Switch on the ZigBee HA profile. But I’m not using a SmartThings hub for mine, I’m using an Ecobee Smart thermostat (not the newer ecobee3, but the original “Smart”) with the ZigBee add-on. Did you get the hub to see the switch? Read in the instructions how to use a magnet to put it in discovery mode.

        • Nick Harkins

          I got the 73A00-3ZB LCM (switch) to work on the SmartThings Hub. It is great. I intend to plink away at it as time permits to get more than scheduling and on/off.

          I believe I was told by SmartThings’ Tech Support that the ST ZigBee HA profile includes enhancements to include parts of the ZigBee HA Pro profile, or I read that on their forums.

          It is interesting that when the switch is open, (the power is off) the switch’s LED is on! The manufacturer calls this in “override” mode. When the power is on, the LED blinks once per second.

          This is counter-intuitive to say the least.

          Thanks for convincing me to start my journey to get this to work.

          By the way, SmartThings says they have another load control module that is certified by SmartThings. Its on their Compatibility List:


          • Awesome news, Nick. And I noticed the same thing about that LED. Extremely counter-intuitive, and I had to also look it up. LOL. Please keep in touch as to your progress, and perhaps check in from time to time over on I set up that forum to be a non-specific home automation site, for exactly this type of stuff. I know there are lots of us trying to pretty much do the same things. 🙂

  • Hello – I really liked this article! I’m getting into the whole home automation thing. I don’t have the ZigBee or Ecobee Smart products but would love to have the capability to turn my water heater on/off via smartphone or laptop. It would be nice to know of my water heater’s efficiency too. Can you recommend any wifi water heater timers or monitors that work just with a home network and outside of the ZigBee or EcoBee systems? Thank you and keep up the great posts!

    • Nick

      I have been looking for months and the suggestion here is the cleanest. I just ordered the SmartThings Hub form Zigbee and the :Leviton 73A00-3ZB from Amazon. I think this is just the combination that the Dr. ordered. My suggestion: Don’t Fight the Facts.

  • Capt Maniac

    I bought an Ecobee EMS some time ago and installed it at the same time we have new HVAC installed this spring. I checked with Ecobee and the said they no longer sold or supported the Zigbee module. I would like to be able to control my water heater while traveling. Would you consider using the SmartHub for this and future home automation needs? If not, what would you recommend?

    • Hi, Capt. Yes – the SmartThings hub is a good choice for that.

      • Nick Harkins

        Seven months ago I wrote here that I installed a 73A00-3ZB LCM and I was very happy with the setup using a ST hub ver 1. The “device type” was written by another user, but he admits that it was not a finished product. To make a long story short, I have been struggling with my setup since the beginning of November when ST began changing their systems. The biggest problem I have been experiencing is that some days the smart apps that turn it on and off are ignored. I have an alarm set to wake me at 6AM so I can verify that the heater fired up, and yesterday it did not, but today it did. When it doesn’t fire up, I also have to manually turn it off, so it is a pain in the rear. I am beginning to think that it may be a particular problem with ST and Zigbee, because of have several Z-Wave devices at my home and at a remote location that did not experience these problems, including a Z-Wave switch that controls a gas hot water heater. I am almost ready to replace my 73A00-3ZB. If you are groovy programmer you might be able to clean up the driver to eliminate that as an issue. Search the ST community forums for 73A00-3ZB and you will discover the experiences I have had.

  • Hi, Captain! I haven’t messed with the Aeotec, and while the 40A support is a good thing, if your device only needs 30A, it’s a feature that won’t make much difference. My Leviton units have been bulletproof since originally writing this post, but Aeotec products have excellent reviews on Amazon. Maybe this is one of those situations where there’s no wrong answer! 🙂

  • I don’t, because I believe the thermostat on electric water heaters are usually tiny little flathead screw adjustments. All I’ve been able to do is turn on and off. It might be that your only solution is a “smart” water heater that has that type of functionality built in. The Gas Water Heater Timer (Google my review of it) will allow you to adjust thermostat for gas water heaters, but I haven’t found anything reliable for electric. 🙁