SUN-5-12K-SG01HP3-EU-DM2 three-phase hybrid (warning codes)
Deye W09 error code
External fan 3 warning.
Likely causes
- Fan 3 not connected
- Fan 3 failure
- Fan 3 obstructed
Checks to run, in order
- 1Check the fan 3 connector
- 2Check that fan 3 runs
- 3Clean the fan
Fixes
- Reconnect or replace fan 3
- Clear the obstruction
When to escalate
If fan 3 runs correctly and W09 persists, the distributor should check the fan feedback circuit.
Fix it with the right tools
Check the system around the fault before replacing parts: load, battery bank, PV string and commissioning settings. If you need a second opinion, send the code and your inverter model to our team.
Before you open the inverter
- Isolate both the AC and DC sides, then confirm the display is dead before touching terminals.
- Use insulated tools and one hand where possible. DC arcs do not self-extinguish like AC.
- If you see burnt terminals, swollen cells, leaking electrolyte or a burning smell, stop and escalate instead of resetting the fault.
Questions installers ask
What does Deye W09 mean?
External fan 3 warning.
How do I fix Deye W09?
Reconnect or replace fan 3 Clear the obstruction
When should I escalate Deye W09?
If fan 3 runs correctly and W09 persists, the distributor should check the fan feedback circuit.
Can I reset Deye W09 myself?
Only after isolating the AC and DC sides and running the checks above. If Deye W09 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show Deye W09?
Deye W09 is documented for SUN-5-12K-SG01HP3-EU-DM2 three-phase hybrid (warning codes). Confirm the code on your own unit's display or manual before ordering parts.
More Deye error codes
- Deye F01PV input polarity is reversed at one or both DC inputs.
- Deye F02PV insulation resistance to earth is below the safety limit.
- Deye F03Ground fault detected on the PV array (GFDI).
- Deye F04GFDI ground-failure alarm: the PV array or inverter is not properly earthed.
- Deye F05Control-board EEPROM read failure.
- Deye F06Control-board EEPROM write failure.
Guidance reviewed 17 October 2026 by the Mishka Energy installer team. Error codes vary by brand, model family and firmware; confirm against the manufacturer manual.
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