29Fault

DEYE inverter error 29 (F029)

AC load switch failure

Also displayed as F029 / F29 on some models.

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

The exact meaning depends on your model:

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 load switch failureThe AC load switch failed. The manual notes this code has hardly ever appeared in the field.

Cause: The AC load switch failed to operate correctly.

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.62 · 065_BManual_SUN-7_7.5_8K-G02P1-EU-AM2_20260625_en_4466f08b.pdf, p.52 · 032_BManual_SUN-9_10_10.5K-G02P1-EU-AM2_20260625_en_df0f2106.pdf, p.52

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 load switch failureThe AC load switch failed.

Cause: The AC load switch failed to operate correctly.

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.62 · 042_BManual_SUN-120_125_130_135_136K-G01P3-EU-AM8_20260702_en_05f936e3.pdf, p.61 · 060_BManual_SUN-60_70_75K-G01P3-EU-AM8-LV_20260701_en_f559aeec.pdf, p.61 · +1 more official manuals

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 load switch failureThe AC load switch failed.

Cause: The AC-side load switch (output relay path) did not switch correctly.

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.57

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 load switch failureThe AC load switch failed.

Cause: The AC-side load switch (output relay path) did not switch correctly.

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.54 · 036_BManual_SUN-3_4_5_6_7_8_9_10_12_15K-G06P3-EU-BM2_20250506_en_0eb78440.pdf, p.57

Also applies to:SUN-3.6K-SG05LP1-EU-SM2-PSUN-5K-SG05LP1-EU-SM2-PSUN-6K-SG05LP1-EU-SM2-PSUN-7K-SG05LP1-EU-SM2-PSUN-7.6K-SG05LP1-EU-SM2-PSUN-8K-SG05LP1-EU-SM2-PSUN-10K-SG05LP1-EU-SM2-PSUN-7.6K-SG01LP1-EU+21

What it means

Parallel CANBus faultParallel CAN bus communication fault.

Cause: In parallel mode, the parallel communication cable is badly connected or the inverter communication address is set incorrectly. Inverters also report F29 normally during the parallel system startup period until all units are ON.

How to fix it

  1. Check the parallel communication cable connection and the hybrid inverter communication address setting.
  2. During the parallel system startup period F29 is expected; when all inverters are in ON status it disappears automatically.
  3. If the fault still exists, contact Deye for help.

Source: 039_BManual_SUN-3.6_5_6_7_7.6_8_10K-SG05LP1-EU-SM2-P_20260428_en_70c401a6.pdf, p.50 · 043_BManual_SUN-12_14_16K-SG01LP1-EU_20260519_en_703e15ac.pdf, p.46 · 052_BManual_SUN-_3.6-6_K-OG01LP1-EU-AM2_20260406_en_dc31b173.pdf, p.45 · +4 more official manuals

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

Parallel Communication FaultParallel_Comm_Fault - communication fault between paralleled inverters.

Cause: The parallel communication cable connection or the hybrid inverter communication address setting is incorrect; F29 also appears normally during parallel system startup until all inverters are in ON status.

How to fix it

  1. When inverters are connected in parallel, check the parallel communication cable connection and the hybrid inverter communication address setting
  2. During the parallel system startup period, inverters will report F29; when all inverters are in ON status, it disappears automatically.

Source: 037_BManual_SUN-5_6_8_10_12_15_20_25K-SG01HP3-EU-AM2_20260224_en_9ef2717c.pdf, p.50 · 050_BManual_SUN-29.9_30_35_40_50K-SG01HP3-EU-BM3_4_20260224_en_544e1b2f.pdf, p.51 · 062_BManual__SUN-60_70_75_80K-SG02HP3-EU-EM6_20260224_en_38cbc9f6.pdf, p.51

Also applies to:SUN-5K-SG02LP2-US-AM2SUN-6K-SG02LP2-US-AM2SUN-7.6K-SG02LP2-US-AM2SUN-8K-SG02LP2-US-AM2SUN-10K-SG02LP2-US-AM3SUN-12K-SG02LP2-US-AM3SUN-5K-SG04LP3-EUSUN-6K-SG04LP3-EU+15

What it means

Parallel CAN Bus Fault

Cause: In parallel mode, the parallel communication cable connection or the hybrid inverter communication address setting is incorrect; F29 also appears normally during parallel system startup until all inverters are in ON status.

How to fix it

  1. In parallel mode, check the parallel communication cable connection and the hybrid inverter communication address setting
  2. During the parallel system startup period, inverters will report F29; when all inverters are in ON status, it disappears automatically
  3. If the fault still exists, contact us for help.

Source: 059_BManual_SUN-5_6_7.6_8_10_12K-SG02LP2-US-AM2_AM3_20260406_en_fb6a30c7.pdf, p.54 · 038_BManual_SUN-5_6_8_10_12K-SG04LP3-EU_20260319_en_081932c1.pdf, p.47 · 040_BManual_SUN-3_4_5_6_8_10_12K-SG05LP3-EU-SM2_20260319_en_b0183b7d.pdf, p.47 · +1 more official manuals

AI-W5.1 ESS

Energy storage systemFault

Also applies to:AI-W5.1-5P3-EU-B-ESSAI-W5.1-6P3-EU-B-ESSAI-W5.1-8P3-EU-B-ESSAI-W5.1-10P3-EU-B-ESSAI-W5.1-12P3-EU-B-ESS

What it means

Parallel CAN Bus faultParallel CAN communication fault.

Cause: In parallel mode, the parallel communication cable connection or inverter communication-address setting is wrong; inverters also report F29 transiently during parallel-system start-up.

How to fix it

  1. Check the parallel communication cable connections and the communication address setting of each inverter.
  2. During start-up it disappears automatically once all inverters are ON; if it still exists, contact Deye for help.

Source: 002_Download_4e90fe7a.pdf, p.47

GB-SL / GB-SL Pro ESS

Energy storage systemFault

Also applies to:GB-SL5K-EUGB-SL6K-EUGB-SL8K-EUGB-SL10K-EUGB-SL12K-EUGB-SL15K-EUGB-SL20K-EUGB-SL Pro 5K-EU+6

What it means

Parallel_Comm_FaultParallel CAN communication fault.

Cause: In parallel mode, the parallel communication cable connection or inverter communication-address setting is wrong; inverters also report F29 transiently during parallel-system start-up.

How to fix it

  1. Check the parallel communication cable connections and the communication address setting of each inverter.
  2. During start-up it disappears automatically once all inverters are ON; if it still exists, contact Deye for help.

Source: 081_deye_gb_sl_pro_user_manual_46fa941a.pdf, p.50 · 010_Download_cc05df18.pdf, p.45

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

What it means

EEPROM errorThe BMS could not read or write its EEPROM memory.

Cause: The non-volatile memory holding BMS calibration and configuration failed a read/write - an internal memory fault.

How to fix it

  1. Restart the battery.
  2. If the code persists, contact Deye support for BMS repair or replacement.

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_INTERNAL_COMM_ERRORThe internal CAN communication fails.

Cause: The internal CAN bus between BMS components dropped - loose internal wiring or a board fault.

How to fix it

  1. Restart the system.
  2. If the fault persists, contact Deye support.

Source: 008_deye_ess_user_manual_gb_a_jpnen_v02_20250829_3fea617e.pdf, p.13

Frequently asked questions

What does error 29 mean on a DEYE inverter?
It depends on the model — 15 devices use code 29. On the SUN G01P3-EU-BM8 Series it means: AC load switch failure. The card for each model on this page gives its exact meaning and fix.
Is error 29 a fault or a warning?
29 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 29?
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

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.