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ErrorLib — Industrial Fault Code Library

Disclaimer: ErrorLib is an independent technical reference tool. While we aim for accuracy, always verify with the manufacturer’s official service manuals before performing maintenance on industrial equipment. ErrorLib is not affiliated with the brands listed.

721

EEPROM has been re-initialised

Fronius · Solar Energy

What does 721 mean?

The EEPROM (Electrically Erasable Programmable Read-Only Memory) has been re-initialised, possibly due to a reset or an internal event. A warning message is shown on the display.

Common Causes

  • System reset
  • Internal data corruption or re-initialisation process

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Acknowledge the status code on the display

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

1Hardware fault102AC voltage too high103AC voltage too low
Source: Fronius Solar Energy
Open Manual (Page 129)Search more codes in this manual