Can one ZWave Switch Send Commands to Another?

(Scottpsu) #1

I have some small fans that I use to cool my home theater equipment - specifically, one piece that tends to warm up a lot during use. Last week, I purchased the GE Outdoor Lighting Control Switch (outdoor version was cheaper than indoor version), added it to my SmartThings Hub, plugged the fans into them, and now i can remotely turn the fans on and off as needed.

Now, I’d like to further automate this process so that the fans start as soon as I begin using the equipment - this will avoid the possibility of me forgetting to turn them on when I turn on the home theater equipment.

I’ve been thinking about this for a week now, and have yet to come up with a way to do this that will work as fluidly and automatically as I’d like. The switch is not connected to a dedicated electrical outlet and I don’t want to install one, so getting a ZWave receptacle is not an option.

So far, my best option would be to associate the powering on (and off) of the fans to an activity I do only when I use the equipment, and utilize SmartThings devices to correlate the fans to it. The activity that makes the most sense is the turning on of a light outside the movie room. This light only gets turned on when I am watching movies, and as a bonus, it has a dedicated decora switch.

if I were to replace the current decora switch with a ZWave switch, is there a SmartApp that, when pressed, would both turn on the light and send a command to the outdoor switch to turn on the fans? And, of course, I would want the opposite: when I turn off that light, the switch would send a “power off” command to the switch controlling the fans.

I looked through all the SmartApps and could not clearly identify one that would do this, as they all tend to send commands to the appliance connected to the SmartThings switch, rather than send commands to other switches.

I hope this makes sense; please let me know if I need to elaborate, and thanks for your assistance!



(Chrisb) #2

Yes, there’s a couple of apps that would do that. There is one that lets you specify a master switch that when it’s turned on turns on any other switchs/outlets and when turned off, turns off others. This would probably be the best option.

There’s also my Wireless 3-way app which would do the same thing and would work for you as well. Rather than specify a master switch my program will just toggle all group switches/outlets on and off if anyone one of them is turned on or off.

Now, having said that, there’s another a few other options you can think about if you want something even more automated. First, something that can be done right now: Get one of the devices that measure temp (SmartThings multi or Aeon Motion Sensor+) and have this devices close to your equipment. It shouldn’t be too hard to write a program that watches temp and when it goes above a specified level turns on the switch/outlet that the fan is plugged into and keeps it on until the temp falls below a specified level.

Second, there are some devices that measure when current is running to a device or not. You could connect this to your equipment so that when you turn it on it turns on the fan. I don’t know if SmartThings has implemented support yet for these, but I suspect it’s coming if it isn’t here yet.

(Scottpsu) #3

Thanks. Your suggestion of using a SmartSense Multi as a temperature sensor is exactly what I am doing, for the time being. There is a SmartApp called “virtual Thermostat” that will turn on a switch or outlet once the Multi’s temperature reaches a proscribed number.

For the most part, it works pretty well. I’d prefer to have the fans kick on as soon as the equipment is turned on, but I can live with the small delay. On the other end, the fans stay on for a few minutes after the equipment is shut down, which isn’t a bad thing.

I might try a “master switch” option; need to find and examine that SmartApp.

I was trying to avoid any solution that requires me to electrically connect the fans directly to the equipment; for audiophile purposes, I’d rather not do that.

Thanks so much for your post! Very helpful.



(Charlie Treadwell) #4

What is the name of the app you’re referring tow in your first paragraph?

(Cindy) #5

If you get a more expensive Zwave light switch like the one from Cooper you can directly associate the GE zwave directly to the Cooper light switch, no app from Smart Hub needed. However you will need the Aeon Minimote to do it, as I don’t think you can do the native zwave association in ST, but the minimote can do it.

(Brian Smith) #6

I did this recently with Linear switches (a load bearing one and a virtual three way accessory switch) and a minimote. Love the minimote.

(Beckwith) #7


It is “The Big Switch”, you can find in SmartSetup | More | Convience.

(Scottpsu) #8

It used to be called “Virtual Thermostat” - at least, that’s what it was called when I first set it up. In the new iOS app, I am having a very hard time finding a master list of SmartApps, so I can’t be sure if it’s still called that. Sorry!

(Charlie Treadwell) #9

Thanks! This is a great app for someone who was duped into buying Hue bulbs.