Trigger a light based on temperature?

I am hoping to use a SmartThings Multipurpose sensor to trigger a switch to turn on when the temperature goes below a set value.

I can’t see a way to do that in Smart Lighting, Routines, or Smart Home Monitor.

Am I blind, or am I going to have to resort to CoRE or IFTTT for this? So far I have managed to keep all my automations eligible to run locally, and I was hoping to continue that.

In case you’re wondering - when I set Away mode, a Smart Lighting automation turns off the power to the water heater, as there is no sense in running it when no-one is home. If the temperature inside the condo drops low enough for one or more of the five thermostats to kick in (unlikely unless it is frigid outside), the heating system will come on and will draw water from the water heater. It would be more effective if that water was hot :grin:


One of the climate control smart apps should work. i.e it’s to Cold App.

Thanks. Does that run locally?

Not sure, it is by Smartthings I would hope there apps run locally.


At present none of the smartapps run locally, official or not, except for smartlighting and a few parts of smart home monitor. Even routines don’t run locally.

And smart lighting only runs locally with a specific subset of devices.

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Stand corrected, Thanks.

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Thanks all. I had previously confirmed I was “complying” with the setup that @JDRoberts linked to for local processing, but in this case since there’s no alternative I’ll look at It’s Too Cold (thanks @Jason_Brown for the reference).


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Hi Jason. I found very useful the “it’s too cold” app. It can be used too power on a smartplug switch. But now I need a similar app “it’s too hot” function to power off the smartplug switch and I can not find it.
Could you help me?

I have a slightly different temperature trigger need. I would like to change my Mode from “Home” to a new mode: “Home—it’s Bitter Cold Ourside” when temperature drops below 15 degrees. I will then use that mode to trigger a different set of routines to suspend nightly thermostat dipping as recovery in morning is way too long when it is bitter cold outside. The standard routines don’t have a trigger on temperature. Any ideas? I tried coding something, but to date I have not gotten the code to work. Mode never changes.

Use anything which does trigger on temperature to turn on a virtual switch. Then have that virtual switch coming on start the routine that changes the mode. Or just use webcore and you won’t need the virtual switch. :sunglasses:

How to Get Started Creating Complex Rules in SmartThings (2017) (SmartThings Classic)

Thanks, JD. It sounds wonderful and everything I read in your link sounds exactly what I’m looking for. I cannot for the life of me figure out the first steps to use WebCore. Do I set it up as a SmartApp in my smartthings account? Is there website I go to to set up my rules? Where is the tutorial for using this? Also, how do I add a virtual switch? When I select “+ Add a Thing” in the classic app, it goes right into search mode looking for a physical thing. Do I manually add it?

WebCore is itself a smart app, just a very complicated one.

The best thing is to go to the webcore forum. They have their own tutorials, their own wiki, video instruction, and lots of people to help you. :sunglasses:

Here’s the FAQ for adding a virtual device. You either have to create it with code yourself in the web interface to your account, which is called the IDE, or you have to use one of the smartapps which can create them for you.

I think I’ll just set this up with Stringify for now. However, Stringify won’t let me set up a “Home-Bitter Cold” mode. I’d like to use that idea you suggested of having it set a virtual switch, but I just don’t know how to create a virtual switch.

We Cross posted: I just gave you the FAQ for creating a virtual device in my previous post.

Meanwhile, the following FAQ might also be helpful. Stringify works the same way as IFTTT in this regard.

Ahhh…I see. I’ll try tracking down one of those apps to create a virtual switch. Thanks for the tips!

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I read through the webcoRE community forum and watched some of the instructional videos. Gathering up all the courage I could muster, I dove in and set up webcoRE and built my first piston setting the state of a virtual switch based on outside temperature retrieved from rBoy’s weather station. I then built a routine that changed my location mode from “Home” to “Home-Bitter Cold” based on the virtual switch position. My goodnight thermostat routine is then suspended from running when I’m “Home-Bitter Cold” so as to avoid suffering the next morning with a slow warm up. I’m looking forward to the next deep freeze to see how this works. Thanks JD for pointing me in the right direction.

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