What is the lowest set temperature on the ITC-308 WIFI?

I am attempting to use this unit to run the furnace in my garage. How low am I able to set the temperature? I see the probe is capable of -40F but I’m curious how low the unit can go. Is it fully adjustable on the App? Am i able to plug in my furnace to the heat plug and set the unit to 25F and it will turn on and off accordingly?

The probe temperature range of ITC-308WIFI is -40~100°C/-40~212°F, but please note that the probe and wire cannot directly touch the fire.
The temperature range that the ITC-308WIFI body can withstand is -20~ 60 °C / -4~ 140 °F, and the humidity is 20~85% (No Condensate)
Please refer to the principle of ITC-308WIFI: