The S1 is a single-circuit IoT heat trace controller for use in snow melting, freeze protection and temperature maintenance applications. The device can drive up to a 30A resistive load to control electric heat trace systems operating between 100 VAC and 277 VAC. The S1 comes in an outdoor rated enclosure tested to IP67 standards.


Control Modes

  • Smart Snow Melting: Uses weather data to activate the heating system, includes optional preheating, the ability to ignore light storms, and dynamic heating after the storm, all to improve overall system performance and reduce energy use and operating cost (For use on snow melting and gutter systems)
  • Snow/ice sensor: Connects to a snow or ice sensor (this mode can be used as an offline back up to smart snow melting)
  • Temperature Sensor: Connects to a thermistor to maintain system temperature (For use on freeze protection and process temperature maintenance systems)
  • Uses an ambient temperature: (local sensor or cloud-based temperature) signal to activate the device (For freeze protection systems)

Power Ratings

  • Supply Voltage – 100 to 277 VAC 50/60 Hz
  • Load - Maximum 30 A, 100 to 277 VAC resistive


  • Programmable from 5 mA to 300 mA (default 30 mA)
  • Manual and automatic test

Sensor Inputs

  • Temperature: Thermistor
  • Temperature: RTD (2 or 3 wire)

Enclosure / Environment

  • Outdoor rated (tested to IP67 standards)
  • Operating Temperature -30˚C to 70˚C

Low Voltage Outputs

  • Dry Contact Alarm (configurable)


  • Download the Frio App for installation instructions


  • WiFi 802.11 Dual Band 2.4GHz & 5GHz
  • Ethernet (RJ45, Cat 5 or 6)
  • Cellular (S1-C)
  • RS485 (Modbus, BacNet)