12Fault

DEYE inverter error 12 (F012)

AC auxiliary contactor errors

Also displayed as F012 / F12 on some models.

Fault — the inverter cuts its output and the red LED stays solid until the fault is cleared.

The exact meaning depends on your model:

SUN G01P3-EU-BM8 Series

InverterFault

Also applies to:SUN-120K-G01P3-EU-BM8SUN-125K-G01P3-EU-BM8SUN-130K-G01P3-EU-BM8SUN-135K-G01P3-EU-BM8SUN-136K-G01P3-EU-BM8SUN-7K-G02P1-EU-AM2SUN-7.5K-G02P1-EU-AM2SUN-8K-G02P1-EU-AM2+3

What it means

AC auxiliary contactor errors — The auxiliary AC contactor did not operate correctly. The manual notes this code has hardly ever appeared in the field.

Cause: The auxiliary AC contactor failed to switch as commanded or returned an implausible feedback state.

How to fix it

Restart the inverter; if the code persists after the restart, contact your installer or Deye service and provide the inverter serial number, the installation date and the displayed error code.

Source: 041_BManual_SUN-120_125_130_135_136K-G01P3-EU-BM8_20251021_en_a2166559.pdf, p.61 · 065_BManual_SUN-7_7.5_8K-G02P1-EU-AM2_20260625_en_4466f08b.pdf, p.51 · 032_BManual_SUN-9_10_10.5K-G02P1-EU-AM2_20260625_en_df0f2106.pdf, p.51

SUN G03/G01P3-AM8 Series

InverterFault

Also applies to:SUN-60K-G03SUN-70K-G03SUN-75K-G03SUN-80K-G03SUN-90K-G03SUN-100K-G03SUN-110K-G03SUN-60K-G01P3-EU-AM8-LV+7

What it means

AC auxiliary contactor errors — The auxiliary AC contactor did not operate correctly.

Cause: The auxiliary AC contactor failed to switch as commanded or returned an implausible feedback state.

How to fix it

Restart the inverter; if the fault is not ruled out, contact the installer or the manufacturer's customer service.

Source: 033_BManual_SUN-70_75_80_90_100_110K-G03_20260702_en_a9db1e1b.pdf, p.60 · 042_BManual_SUN-120_125_130_135_136K-G01P3-EU-AM8_20260702_en_05f936e3.pdf, p.60 · 060_BManual_SUN-60_70_75K-G01P3-EU-AM8-LV_20260701_en_f559aeec.pdf, p.60 · +1 more official manuals

SUN G04/G05/G06 3-Phase

InverterFault

Also applies to:SUN-6K-G06-LV-P1SUN-8K-G06-LV-P1SUN-6K-G06P3-EU-BM2-LV-P1SUN-8K-G06P3-EU-BM2-LV-P1SUN-10K-G05-LVSUN-12K-G05-LVSUN-15K-G05-LVSUN-15K-G06P3-EU-BM2-P1+27

What it means

AC auxiliary contactor errors — The AC auxiliary contactor did not operate correctly.

Cause: The auxiliary AC contactor failed to open or close as commanded, or its feedback signal is wrong.

How to fix it

Restart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.

Source: 063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf, p.56

SUN G04P1/G05P1 Series

InverterFault

Also applies to:SUN-1K-G04P1-EU-AM1SUN-1.5K-G04P1-EU-AM1SUN-2K-G04P1-EU-AM1SUN-2.2K-G04P1-EU-AM1SUN-2.5K-G04P1-EU-AM1SUN-2.7K-G04P1-EU-AM1SUN-3K-G04P1-EU-AM1SUN-3.3K-G04P1-EU-AM1+36

What it means

AC auxiliary contactor errors — The AC auxiliary contactor did not operate correctly.

Cause: The auxiliary AC contactor failed to open or close as commanded, or its feedback signal is wrong.

How to fix it

Deye states this code has hardly ever appeared in the field; contact your installer or Deye service if it occurs.

Source: 031_BManual_SUN-1_1.5_2_2.2_2.5_2.7_3_3.3_3.6_4K-G04P1-EU-AM1_20260624_en_15adc00c.pdf, p.53 · 036_BManual_SUN-3_4_5_6_7_8_9_10_12_15K-G06P3-EU-BM2_20250506_en_0eb78440.pdf, p.56

SUN SG01HP3/SG02HP3 Hybrid

InverterFault

Also applies to:SUN-5K-SG01HP3-EU-AM2SUN-6K-SG01HP3-EU-AM2SUN-8K-SG01HP3-EU-AM2SUN-10K-SG01HP3-EU-AM2SUN-12K-SG01HP3-EU-AM2SUN-15K-SG01HP3-EU-AM2SUN-20K-SG01HP3-EU-AM2SUN-25K-SG01HP3-EU-AM2+9

What it means

AC Slave Contactor Failure — AC_SlaveContactor_Failure - the slave AC contactor (relay) reported a fault.

Cause: The slave AC contactor of the inverter failed its check or did not switch correctly.

How to fix it

Restart the inverter 3 times and restore the factory settings.

Source: 037_BManual_SUN-5_6_8_10_12_15_20_25K-SG01HP3-EU-AM2_20260224_en_9ef2717c.pdf, p.49 · 050_BManual_SUN-29.9_30_35_40_50K-SG01HP3-EU-BM3_4_20260224_en_544e1b2f.pdf, p.50 · 062_BManual__SUN-60_70_75_80K-SG02HP3-EU-EM6_20260224_en_38cbc9f6.pdf, p.50

RW Spring Series Battery

BatteryFault

Also applies to:RW-L2.5ARW-L5.1RW-L10.2RW-F16SE-F5SE-F5 PlusSE-F5 ProSE-F12+7

What it means

Cell temperature over difference — The temperature spread across the pack exceeded the allowed difference.

Cause: Uneven heating or cooling around the pack (partial exposure to a heat source or draft) or a drifting temperature sensor produced an abnormal temperature gap between cells.

How to fix it

  1. Check the battery is not partially exposed to a heat source or cold draft and let temperatures equalize.
  2. If the code returns with the pack evenly tempered, contact Deye support.

Source: 093_Deye_RW-L2.5A_User_Manual_EN_89188fb8.pdf, p.10 · 019_Download_4a609b7e.pdf, p.10 · 021_Download_f81ba1e7.pdf, p.10 · +6 more official manuals

GB-A HV Battery

BatteryFault

Also applies to:GB-A

What it means

ALARM_ID_NORTH_CONNECTOR_OVER_TEMP_LEV_2 — The temperature of the BMS connector is too high.

Cause: A loose or high-resistance connection at the BMS power connector heated up under current.

How to fix it

  1. Switch off, let it cool, and check/re-seat and torque the BMS connector and cabling.
  2. Contact Deye support if the heating returns.

Source: 008_deye_ess_user_manual_gb_a_jpnen_v02_20250829_3fea617e.pdf, p.13

Frequently asked questions

What does error 12 mean on a DEYE inverter?
It depends on the model — 10 devices use code 12. On the SUN G01P3-EU-BM8 Series it means: AC auxiliary contactor errors. The card for each model on this page gives its exact meaning and fix.
Is error 12 a fault or a warning?
12 is a fault code: the inverter cuts its output and the red LED stays solid until it is cleared.
How do I clear or fix error 12?
Restart the inverter; if the code persists after the restart, contact your installer or Deye service and provide the inverter serial number, the installation date and the displayed error code. The exact steps for each affected model are listed on this page.

Related error codes

Other codes on the SUN G01P3-EU-BM8 Series

All SUN G01P3-EU-BM8 Series codes All SUN G02P1-EU Series codes

Other codes on the SUN G03/G01P3-AM8 Series

All SUN G03/G01P3-AM8 Series codes

Other codes on the SUN G04/G05/G06 3-Phase

All SUN G04/G05/G06 3-Phase codes

Other codes on the SUN G04P1/G05P1 Series

All SUN G04P1/G05P1 Series codes All SUN G06P3-EU Series codes

Other codes on the SUN SG01HP3/SG02HP3 Hybrid

All SUN SG01HP3/SG02HP3 Hybrid codes

Other codes on the RW Spring Series Battery

All RW Spring Series Battery codes All SE Spring Series Battery codes

Prefer the full written guide? Read the complete DEYE inverter error-code guide

Compiled from official DEYE user manuals. Always consult your device manual and a qualified technician before performing repairs.