1009 on a Sigenergy SigenStor: AFCI fault. Official suggestion (summarised): Open PV DC switch, inspect for damage/poor contact/burn marks, repair, close DC switch and clear AFCI fault in app
Short answer
On a Sigenergy inverter, 1009 means: AFCI fault. Official suggestion (summarised): Open PV DC switch, inspect for damage/poor contact/burn marks, repair, close DC switch and clear AFCI fault in app. 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: AFCI fault. Official suggestion (summarised): Open PV DC switch, inspect for damage/poor contact/burn marks, repair, close DC switch and clear AFCI fault in app.
Likely causes:
- DC cable damaged, poor contact of string connector.
Is it safe?
Switch the inverter off at its isolator and call an engineer.
| Does the inverter stop? | Yes |
|---|---|
| Severity | Safety lockout |
| Engineer needed? | Yes |
The inverter stops until the fault clears or is reset.
Resetting itself: no (clear in app after repair).
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.
- Do not reset repeatedly; any burning smell - leave off and call installer.
What the engineer will check
- Inspect DC cabling, connectors and terminals for arcing/burn marks.
- Replace damaged parts; clear AFCI fault in app.
- Sub-IDs: ID1-ID16 AFCI fault of string n.
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