1003 on a Sigenergy SigenStor: Over-temperature. Official suggestion (summarised): Restarts after temperature normal; improve ventilation/shade if repeated
Short answer
On a Sigenergy inverter, 1003 means: Over-temperature. Official suggestion (summarised): Restarts after temperature normal; improve ventilation/shade if repeated. The inverter stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: Over-temperature. Official suggestion (summarised): Restarts after temperature normal; improve ventilation/shade if repeated.
Likely causes:
- High ambient temperature, poor ventilation, internal module malfunction.
Is it safe?
| Does the inverter stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The inverter stops until the fault clears or is reset.
Resetting itself: yes.
Manual reset: n/a.
What you can check
- Read the alarm code, name and ID in the mySigen app.
- Report it via mySigen app Support > Troubleshooting (Sigenergy's stated route) or contact your installer.
- Check the unit's vents/decorative cover are not blocked or covered and it is not in direct sun (look only; no cover removal).
What the engineer will check
- Check derating history, fans/heat sink.
- Sub-IDs: ID1 inverter over-temperature.
Who to ask for: battery storage / PV inverter.
Certification: Sigenergy-trained installer; MCS PV/battery installer for certified installs; electrical work to BS 7671.
What you might notice
Sources
- Sigenergy Alarm List (Version 05) ↗ · 05 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026