| Function | Color | Explanation |
| Boiler | Green | On: Boiler request active Off: Boiler request inactive |
| Pump | Green | On: Pump request active Off: Pump request inactive Flashing: Temperature limiter/dew point sensor active |
| Mains voltage | Green | On: Device in operation Off: Device not in operation Flashing: Commissioning mode active |
| Fuse | Red | On: Fuse defective |
| Change over | Blue | On: Cooling mode active Off: Heating mode active |
| 8 room thermostats | Green | On: active thermostat signal, heating request Off: inactive thermostat signal, no heating request Flashing (long – short): active controller signal, heating request, room is currently not participating in load balancing Flashing (long – long): Cooling lock display |
| Factory reset | Red | ower LED flashes red quickly for 5 sec, all other LEDs are off |
| First Open Function | Green/ orange | Power LED flashes alternately green/orange + input LEDs are lighted during function; all other LEDs (pump, boiler, CO, etc.) as in normal mode |
| Manual open function | Green/ orange | Power LED flashes alternately green/orange + CO LED flashes + ; all other LEDs (input LEDs pump, boiler, etc.) as in normal mode |