If you have already made any settings, we recommend that you first reset the ETO2 ice and snow melt control to the factory state.
This is done under Setup → Factory Reset → Reset. Then restart the unit via Exit → Restart.
After the restart, select the following settings:
Celsius
Sensor 1: ETOG
Sensor 2: OFF
Outdoor Sensor: OFF
Application: ELECTRIC 1-ZONE
In this operating mode, all 3 relays are always switched through when the switching thresholds are reached.
The display shows "ZONE 1 HEAT" with "ON" and "ZONE 2 HEAT" with "OFF".