Rancilio Classe 9 (USB and S)
Heat-exchange espresso machine with iSteam option. E codes are faults (mostly supply and short-circuit faults); W codes are warnings about one part or a service prompt.
What it is: Espresso machine
Rancilio Classe 9 (USB and S) error codes
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| E00 | CPU self-check | Control board | Switch off and on; replace the board if it stays. |
| E01 | Boiler fill timeout | No water | Open the supply. |
| E02 | Boiler pressure not reached in time | Heating fault | Check element and controls. |
| E03 / E04 | Boiler pressure sensor shorted / open | Sensor or wiring | Check the sensor. |
| E05 | IDS link missing | Cable | Check the connection. |
| E06 / E07 / E08 | Softener due / maintenance due / cleaning interrupted (logged) | Counters or interrupted clean | Act on the reminder. |
| E09–E12 | 24 V short on group 1–4 | Valve coil or wiring on that group | Find the short. |
| E13 | Short on general outputs (iSteam, lights) | Wiring | Find the short. |
| E14 | Level sensor shorted | Probe or wiring | Check the probe. |
| E15 / E16 / E18 | 12 V short: pressure sensor / flow meter / power board | Wiring or part | Find the short. |
| E17 | External 5 V short | Wiring | Find the short. |
| E19 | Boiler over-pressure | Pressure control | Switch off; check pressure control. |
| W01–W04 | No signal from group 1–4 flow meter | Grind too fine or flow meter fault | Check grind and flow meter. |
| W05 / W06 | iSteam temperature sensor shorted / open | Sensor | Check the sensor. |
| W07 | Check data | Settings problem | Check settings. |
| W08 / W09 / W10 | Maintenance / softener / coffee cleaning due | Counter reached | Act on the reminder. |
| W11 | Check the clock | Time lost | Set the clock. |
| W12–W17 | Group valve 1–4 shorted or open | Coil or wiring | Check the valve. |
| W18 / W19 | Boiler fill valve shorted / open | Coil or wiring | Check the valve. |
| W22–W25 | Tea water (4TEA) cold / hot valve shorted or open | Coil or wiring | Check the valve. |
| W26 / W27 / W30 / W31 | iSteam steam / air valve shorted or open | Coil or wiring | Check the valve. |
| W32 / W33 | Check message file / USB connection | USB | Check the stick and file. |
| W34 | Purge iSteam | Flush needed | Run the purge. |
Other useful key presses
| Task | How |
|---|---|
| Factory reset | Switch on while holding button D of the left group for 5 s. |
For licensed technicians only. This equipment can involve mains voltage, high-voltage microwave circuits, gas and refrigerant. Isolate power (and gas) before opening panels, follow the manufacturer's manual and your local licensing rules (for example ARC refrigerant handling and electrical or gas licences). Wrong settings can spoil food or damage equipment. Check every value on the unit in front of you before changing it.
Based on: Rancilio Classe 9 user manual (2021-06), list of errors. Always check the manual for your exact model and software version.
ServiceModes is not affiliated with Rancilio or any other manufacturer. Written in our own words from the manufacturer's documentation.