Read the ETO2 alarm message before troubleshooting a snow-melting control.
A flashing red ALARM indicator on the SCE-120 / ETO2 can represent several faults. Open the ALARM menu and record the exact message; the light alone does not establish that one particular sensor or terminal pair has failed.
- TEMP SENSOR 1 or TEMP SENSOR 2: the corresponding temperature sensor is defective.
- OUTDOOR SENSOR: the outdoor sensor is defective.
- SENSOR HEATER: the heating element in the ground or roof sensor is short-circuited.
- Water-temperature, supply/return-sensor, and frost-protection messages apply to the hydronic configurations described in the manual.
Have a qualified installer check the model, application setup, and sensor connections against the matching wiring diagram. Disconnect power before wiring work. Do not install a resistor or jumper as a permanent substitute for the required sensor.
The manual’s commissioning test uses the configured sensor and temperature setting, then restores the intended operating setting after the test. Electrical measurements and any test that energizes the system belong with a qualified installer. Contact WarmlyYours Technical Support at (800) 875-5285 with the displayed alarm and installation details.
Sources
- Manufacturer instructions (publication 13472), PDF pp. 5–7 and 65.