240V / 4000 Watt Shop Heater

Hi - I’m looking for recommendation on controlling a 240V / 4000 Watt Shop Heater via SmartThings.

This is for a garage/workshop located in the mountains, so this will need to serve two purposes. First as freeze protection (e.g. keeping the space from getting below 36 degrees) and second to pre-heat the workshop remotely to a desired temperature.

The following heater is something that I had in mind, but I’m open to suggestions.


Thanks in advance!

Does it have to be a plug-in style heater? I have a heater similar to the link below and have it setup to use a low voltage remote thermostat. It has to be hard-wired to its own breaker… BUT if you have a 240V receptacle/outlet already in the wall, the wiring could be extended to the ceiling to the heater location.

I just ordered my smartthings stuff and I will be setting mine up to use either a multi-sensor or an aeon labs multi sensor and use that as my temperature sensor/occupany sensor. Then use a z-wave/zigbee low voltage relay or switch to turn the heater on/off.


Using a remote thermostat gives you the ability to control the heater without having to deal with switching the 240V power circuit.

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Here is another option if you are not going with @fstbusa option. Depend on your heater you can have this Aeon labs inline controller but most fan heaters have a cool down before power cutoff so both options could be a no go if that’s the case. Unless you can find a smartapps to monitor the power usage of the heater and only shutoff when wattage is at 0.

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The option I used won’t affect my shutdown… My heater runs the fan after the heat has shutoff and using the “thermostat” wiring doesn’t affect the built in cooldown cycle.


Thank you @fstbusa and @Navat604 !!

Good point about the “cool down” period! Didn’t think about that. :-/

@fstbusa - I like the idea of using a remote thermostat! Which thermostat are you using?

Take your pick… I just happen to be using a Trane programmable thermostat right now but I’ve also used a honeywell mechanical thermostat.

If you want to automate the heater, just use a smart sensor with a temperature sensor. Then you can use a switch to turn on/off the heater… The heaters with remote thermostats just “connect” the thermostat wires together to trigger the heater to come on just like a switch.

Just wire 1 wire on the “in” side and one on the “out” side. Or you can use something like this.