Manitowoc Ice Machine Error Code E28: AuCS Board Not Detected
E28 is an information entry in the Event Log of a Manitowoc Indigo ice machine. It appears when the AuCS automatic cleaning option is selected in the settings but the AuCS board is not detected. It does not stop ice making, so ask whether an automatic cleaning accessory was ever installed and mention the entry at your next service visit.
Low: an information entry; ice making continues normally.
- Code
- E28
- Maker
- Manitowoc
- Equipment
- Ice machines
- Applies to
- Indigo series (non-NXT) control board, Event Log (Service menu > Event Log > View ELog)
What does Manitowoc error code E28 mean?
E28 is an information entry in the Event Log of Manitowoc Indigo ice machines without the NXT display. AuCS is the automatic cleaning system option. A machine has a setting that tells the control board whether the AuCS accessory is fitted. If that setting is selected but the board finds no AuCS board on its connection, it writes E28 as a mismatch note. The entry clears by itself when the hardware is detected, and it does not stop the machine from making ice. So there is no urgency and no alarm, and it is not something a kitchen would notice. The usual reason it shows up is a mismatch between settings and hardware: the option was switched on when no accessory exists, or the accessory is installed but its connection is not being read. The display text for the entry is E28. A technician checks whether the accessory is physically there, what the menu setting says, and the connection between the accessory board and the control board.
Affected models and control systems
Manitowoc Indigo series cubers with the non-NXT control board (Service menu > Event Log > View ELog). E28 only matters on machines where the AuCS cleaning option may be fitted.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- Nothing visible; ice making continues
- The E28 line in the Event Log
- No automatic cleaning cycle if an accessory is fitted
Possible causes
Listed in Manitowoc's documentation
- Whether an AuCS accessory is actually installed
- Setting selected in the menu
- Board connection if the accessory is installed
- Control board communication
Other likely causes — what usually sits behind error code E28 on this control. A technician confirms which one it is before any part is replaced.
- The AuCS setting turned on during a menu change by someone exploring the options
- An accessory that was removed during a past repair while the setting stayed on
- A connector on the accessory board that has loosened and drops the link now and then
Safe checks before calling for service
- Ask whoever manages the machine whether an automatic cleaning accessory was ever installed.
- Note whether the machine is making ice normally.
- Do not change menu settings without guidance.
- Tell us about the entry at your next service visit.
How a technician diagnoses error code E28
- Read the Event Log for E28 and its dates.
- Check the menu to see whether the AuCS option is selected.
- Confirm whether an AuCS board is physically fitted.
- If it is fitted, inspect its connection to the control board.
- Correct the setting or restore the connection as the findings require.
- Menu settings change how the machine behaves, so they should be changed by someone who knows the installed hardware.
- Checking the accessory board connection means opening the control area with line voltage present.
- Telling a setting mismatch from a communication problem takes the machine's own menu data.
How error code E28 differs from similar codes
E28 is a setup-mismatch note, unlike the E19 to E27 entries, which report sensor and probe readings.
Technical reference
- Document
- Indigo Series Technician's Handbook 000014794 5/17, "Event Log" p.87-91
- Maker documentation
- Manitowoc owner support
- Edition
- Part Number 000014794 5/17
- Models / control
- Indigo series (non-NXT) control board, Event Log (Service menu > Event Log > View ELog)
- Section
- Event Log: code list p. 87, Event Log Detail table pp. 88-91 (Service menu > Event Log)
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Manitowoc ice machine error codes
Do I need to do anything about E28?
Not urgently. The machine keeps making ice, but ask a technician to match the setting to the hardware.
Will E28 clear by itself?
Yes, once the AuCS hardware is detected. If no accessory exists, the setting needs to be turned off.
Is E28 a cleaning failure?
No. It does not report a cleaning cycle. It reports that the cleaning accessory board was not found.
Need help with Manitowoc error code E28?
A technician confirms the cause on site and gives you the price in writing before any work starts.