44Fault

DEYE inverter error 44 (F044)

AC Line V,W low voltage

Also displayed as F044 / F44 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-60K-G03SUN-70K-G03SUN-75K-G03+12

What it means

AC Line V,W low voltage — The V-W line voltage is below the protection setting.

Cause: The line voltage between phases V and W is below the protection setting; loose or incorrectly connected AC cables can cause the low reading.

How to fix it

  1. Check the AC voltage protection setting.
  2. Check the voltage difference between the LCD and a meter, and check whether all AC cables are firmly and correctly connected.

Source: 041_BManual_SUN-120_125_130_135_136K-G01P3-EU-BM8_20251021_en_a2166559.pdf, p.63 · 033_BManual_SUN-70_75_80_90_100_110K-G03_20260702_en_a9db1e1b.pdf, p.63 · 042_BManual_SUN-120_125_130_135_136K-G01P3-EU-AM8_20260702_en_05f936e3.pdf, p.62 · +2 more official manuals

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

AC Line V,W low voltage — The V-W line voltage is below the protection setting. Marked 'Not available' in the manual for these models.

Cause: Line voltage protection between phases V and W - a three-phase measurement that is not used on these single-phase models.

How to fix it

  1. Marked 'Not available' in the manual - this code is not used on these models.
  2. If it is displayed nonetheless, restart the inverter and contact your installer or Deye service.

Source: 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

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+48

What it means

AC Line V,W low voltage — The line voltage between phases V and W is below the protection setting.

Cause: Grid V-W line voltage below the protection setting, or AC cables not firmly and correctly connected.

How to fix it

Check the AC voltage protection setting; check the voltage difference between the LCD and a meter; check that all AC cables are firmly and correctly connected.

Source: 063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf, p.58 · 036_BManual_SUN-3_4_5_6_7_8_9_10_12_15K-G06P3-EU-BM2_20250506_en_0eb78440.pdf, p.58

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+15

What it means

AC Line V,W low voltage — Line low-voltage protection for the V-W pair (marked 'Not available' on single-phase models).

Cause: Line-voltage protection for the V-W phase pair; single-phase units have no such line pair, so the code is not used.

How to fix it

Marked 'Not available' on these single-phase models - the code is not used.

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

GB-A HV Battery

BatteryFault

Also applies to:GB-A

What it means

ALARM_ID_HEAT_RELAY_DRIVE_FAULT — Heating relay drive failure.

Cause: The drive circuit for the heating relay failed - heating cannot be switched as commanded.

How to fix it

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

Source: 008_deye_ess_user_manual_gb_a_jpnen_v02_20250829_3fea617e.pdf, p.14

Frequently asked questions

What does error 44 mean on a DEYE inverter?
It depends on the model — 7 devices use code 44. On the SUN G01P3-EU-BM8 Series it means: AC Line V,W low voltage. The card for each model on this page gives its exact meaning and fix.
Is error 44 a fault or a warning?
44 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 44?
Check the AC voltage protection setting. Check the voltage difference between the LCD and a meter, and check whether all AC cables are firmly and correctly connected. 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 G03/G01P3-AM8 Series codes

Other codes on the SUN G02P1-EU Series

All SUN G02P1-EU Series codes

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

All SUN G04/G05/G06 3-Phase codes All SUN G06P3-EU Series codes

Other codes on the SUN G04P1/G05P1 Series

All SUN G04P1/G05P1 Series codes

Other codes on the GB-A HV Battery

All GB-A HV 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.