26Fault

DEYE inverter error 26 (F026)

The DC busbar is unbalanced

Also displayed as F026 / F26 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-BM8

What it means

The DC busbar is unbalancedThe voltages on the two halves of the DC bus are unbalanced.

Cause: The DC bus half-voltages are unbalanced; the 'BUSN' cable or the driver-board power supply cable may be loose.

How to fix it

  1. Check whether the 'BUSN' cable or the driver-board power supply cable is loose
  2. Restart the inverter; if the fault still exists, contact your installer or Deye service.

Source: 041_BManual_SUN-120_125_130_135_136K-G01P3-EU-BM8_20251021_en_a2166559.pdf, p.62

SUN G02P1-EU Series

InverterFault

Also applies to:SUN-7K-G02P1-EU-AM2SUN-7.5K-G02P1-EU-AM2SUN-8K-G02P1-EU-AM2SUN-9K-G02P1-EU-AM2SUN-10K-G02P1-EU-AM2SUN-10.5K-G02P1-EU-AM2

What it means

The DC busbar is unbalancedThe voltages on the two halves of the DC bus are unbalanced. The manual notes this code has hardly ever appeared in the field.

Cause: The voltages on the two halves of the DC bus drifted apart beyond the allowed unbalance.

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: 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

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

The DC busbar is unbalancedThe voltages on the two halves of the DC bus are unbalanced.

Cause: The DC bus half-voltages are unbalanced; the 'BUSN' cable or the driver-board power supply cable may be loose.

How to fix it

  1. Check whether the 'BUSN' cable or the driver-board power supply cable is loose
  2. Restart the inverter; if the fault still exists, contact your installer.

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+48

What it means

The DC busbar is unbalancedThe two halves of the split DC bus are at unequal voltages.

Cause: The 'BUSN' cable or the driver-board power-supply cable is loose, unbalancing the split DC bus.

How to fix it

  1. Check whether the 'BUSN' cable or the driver-board power-supply cable is loose.
  2. Restart the inverter; if the fault still exists, contact your installer or Deye service.

Source: 063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf, p.57 · 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-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+15

What it means

The DC busbar is unbalancedThe two halves of the split DC bus are at unequal voltages.

Cause: The voltages of the two halves of the split DC bus became unequal.

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

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

The DC busbar is unbalancedThe DC busbar voltage is unbalanced.

Cause: When the hybrid inverter runs in split-phase mode and the load on L1 differs greatly from the load on L2, it reports F26.

How to fix it

  1. Wait for a while and check whether it returns to normal.
  2. In split-phase mode, balance the loads on L1 and L2.
  3. Restart the system 2-3 times.
  4. Seek help from Deye if the inverter cannot go back to the normal state.

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

BUS Unbalance FaultBusUnbalance_Fault - the internal DC BUS voltages are unbalanced.

Cause: The load power on the 3 phases differs greatly, or there is DC leakage current.

How to fix it

  1. Wait for a while and check whether it returns to normal
  2. Restart the system 2~3 times.

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-AM3

What it means

DC Busbar UnbalancedThe DC busbar is unbalanced - the internal DC BUS voltages are unbalanced.

Cause: When the hybrid inverter runs in split-phase mode and the load on L1 differs greatly from the load on L2, F26 is reported.

How to fix it

  1. Wait for a while and check whether it returns to normal
  2. Restart the system 2~3 times
  3. Seek help from us if it cannot go back to the normal state.

Source: 059_BManual_SUN-5_6_7.6_8_10_12K-SG02LP2-US-AM2_AM3_20260406_en_fb6a30c7.pdf, p.54

Also applies to:SUN-5K-SG04LP3-EUSUN-6K-SG04LP3-EUSUN-8K-SG04LP3-EUSUN-10K-SG04LP3-EUSUN-12K-SG04LP3-EUSUN-3K-SG05LP3-EU-SM2SUN-4K-SG05LP3-EU-SM2SUN-5K-SG05LP3-EU-SM2+9

What it means

DC Busbar UnbalancedThe DC busbar is unbalanced - the internal DC BUS voltages are unbalanced.

Cause: The load power of the 3 phases is very different, or there is DC leakage current.

How to fix it

  1. Wait for a while and check whether it returns to normal
  2. Restart the system 2~3 times
  3. Seek help from us if it cannot go back to the normal state.

Source: 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 · 044_BManual_SUN-14_15_16_18_20K-SG05LP3-EU-SM2_20260319_en_ac7cdbd1.pdf, p.47

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

The DC busbar is unbalanced

Cause: Large load-power differences between the three phases, or DC leakage current, unbalanced the internal DC bus.

How to fix it

  1. Wait a while and check whether it returns to normal; balance the loads across phases and restart the system 2-3 times.
  2. Seek help from Deye if it persists.

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

BusUnbalance_FaultThe DC busbar is unbalanced.

Cause: Large load-power differences between the three phases, or DC leakage current, unbalanced the internal DC bus.

How to fix it

  1. Wait a while and check whether it returns to normal; balance the loads across phases and restart the system 2-3 times.
  2. Seek help from Deye if it persists.

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

Cell voltage sampling failsThe cell-voltage sampling circuit returned invalid readings.

Cause: A fault in the voltage-sampling harness or measurement circuit inside the pack made cell-voltage readings invalid.

How to fix it

  1. Restart the battery.
  2. If the code persists, the pack needs internal service - 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_FUSE_BLOWNBlown fuse.

Cause: The main pack fuse opened - an external short circuit or an extreme over-current event.

How to fix it

Take the battery out of service and contact Deye support; the cause of the over-current must be found and cleared before the fuse is replaced.

Source: 008_deye_ess_user_manual_gb_a_jpnen_v02_20250829_3fea617e.pdf, p.13

Frequently asked questions

What does error 26 mean on a DEYE inverter?
It depends on the model — 15 devices use code 26. On the SUN G01P3-EU-BM8 Series it means: The DC busbar is unbalanced. The card for each model on this page gives its exact meaning and fix.
Is error 26 a fault or a warning?
26 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 26?
1. Check whether the 'BUSN' cable or the driver-board power supply cable is loose. 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.