| Display -2- | Meaning |
| Lights up green for two seconds. | The auxiliary heater has been switched on with -1-„ON“. |
| Lights up red for two seconds. | The auxiliary heater has been switched off with -3-„OFF“. |
| Flashes green slowly for two seconds. | The signal to switch on has not been received. |
| Flashes green quickly for two seconds. | The auxiliary heater is blocked, e.g. because the fuel tank is nearly empty or there is a fault in the auxiliary heater. |
| Flashes red for two seconds. | The signal to switch off has not been received. |
| Lights up orange for two seconds, then green or red. | The battery charge is low, but the switch on/switch off signal was received. |
| Lights up orange for two seconds, then flashes green or red. | The battery charge is low and the switch on/switch off signal was not received. |
| Flashes orange for five seconds. | The battery is discharged and the switch on/switch off signal was not received. |
