| Feature | Color | Explanation |
| Boiler | Green | On: Boiler demand active Off: Boiler demand inactive |
| Pump | Green | On: pump demand active Off: pump demand inactive Flashing: Temperature limiter/dew point monitor active |
| Mains voltage | Green | On: Device in operation Off: Device out of service Flashing: Commissioning mode active |
| Fuse | Red | On: Fuse defective |
| Change over | Blue | On: Cooling mode active Off: Heating mode active |
| Heating zones (HZ) | Green | On: HZ active Off: HZ inactive Flashing: HZ active; No load balancing |