64Fault

DEYE inverter error 64 (F64)

IGBT heat sink high temperature

Also displayed as F64 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

IGBT heat sink high temperatureThe IGBT heat-sink temperature is too high.

Cause: The IGBT heat-sink temperature exceeded the limit - inadequate cooling or high ambient temperature, or a temperature sensor fault, unsuitable firmware, or a wrong model configuration producing a false reading.

How to fix it

  1. Check the temperature sensor; check that the firmware is suitable for the hardware and that the inverter is its right model
  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.64 · 065_BManual_SUN-7_7.5_8K-G02P1-EU-AM2_20260625_en_4466f08b.pdf, p.53 · 032_BManual_SUN-9_10_10.5K-G02P1-EU-AM2_20260625_en_df0f2106.pdf, p.53

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

IGBT heat sink high temperatureThe IGBT heat-sink temperature is too high.

Cause: The IGBT heat-sink temperature exceeded the limit - inadequate cooling or high ambient temperature, or a temperature sensor fault, unsuitable firmware, or a wrong model configuration producing a false reading.

How to fix it

  1. Check the temperature sensor; check that the firmware is suitable for the hardware and that the inverter is its right model
  2. Restart the inverter; if the fault still exists, contact your installer.

Source: 042_BManual_SUN-120_125_130_135_136K-G01P3-EU-AM8_20260702_en_05f936e3.pdf, p.63 · 060_BManual_SUN-60_70_75K-G01P3-EU-AM8-LV_20260701_en_f559aeec.pdf, p.63 · 067_BManual_SUN-60_70_75_80K-G03_20260309_en_a0739b4b.pdf, p.63

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+71

What it means

IGBT heat sink high temperatureThe IGBT heat-sink temperature exceeded its limit.

Cause: IGBT heat-sink over-temperature; it can also be a faulty temperature sensor, firmware not suitable for the hardware, or a wrong inverter model configuration.

How to fix it

  1. Check the temperature sensor; check that the firmware is suitable for the hardware and that the inverter is its right model.
  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.59 · 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.55 · 036_BManual_SUN-3_4_5_6_7_8_9_10_12_15K-G06P3-EU-BM2_20250506_en_0eb78440.pdf, p.59

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

Heat sink high temperature failureThe heat sink temperature is too high.

Cause: The working environment temperature is too high, causing the inverter heat sink to overheat.

How to fix it

  1. Check whether the work environment temperature is too high.
  2. Turn off the inverter for 10 minutes and restart.
  3. 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.51 · 043_BManual_SUN-12_14_16K-SG01LP1-EU_20260519_en_703e15ac.pdf, p.47 · 052_BManual_SUN-_3.6-6_K-OG01LP1-EU-AM2_20260406_en_dc31b173.pdf, p.46 · +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

Heat Sink OvertemperatureHeatsink_HighTemp_Fault - the heat sink temperature is too high.

Cause: The heat sink temperature exceeded the limit; the working environment temperature may be too high.

How to fix it

  1. Check whether the working environment temperature is too high
  2. Turn off the inverter for 10 minutes and restart.

Source: 037_BManual_SUN-5_6_8_10_12_15_20_25K-SG01HP3-EU-AM2_20260224_en_9ef2717c.pdf, p.52 · 050_BManual_SUN-29.9_30_35_40_50K-SG01HP3-EU-BM3_4_20260224_en_544e1b2f.pdf, p.53 · 062_BManual__SUN-60_70_75_80K-SG02HP3-EU-EM6_20260224_en_38cbc9f6.pdf, p.53

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

Heat Sink High TemperatureHeat sink high temperature failure - the heat sink temperature is too high.

Cause: The heat sink temperature exceeded the limit; the working environment temperature may be too high.

How to fix it

  1. Check whether the working environment temperature is too high
  2. Turn off the inverter for 10 minutes and restart
  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.55 · 038_BManual_SUN-5_6_8_10_12K-SG04LP3-EU_20260319_en_081932c1.pdf, p.48 · 040_BManual_SUN-3_4_5_6_8_10_12K-SG05LP3-EU-SM2_20260319_en_b0183b7d.pdf, p.48 · +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

Heat sink high temperature failureHeat sink temperature is too high.

Cause: The inverter heat-sink temperature exceeded its limit - working environment temperature too high or insufficient cooling.

How to fix it

  1. Check whether the work environment temperature is too high; turn the inverter off for 10 minutes and restart.
  2. Seek help from Deye if it does not recover.

Source: 002_Download_4e90fe7a.pdf, p.48

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

Heatsink_HighTemp_FaultHeat sink temperature is too high.

Cause: The inverter heat-sink temperature exceeded its limit - working environment temperature too high or insufficient cooling.

How to fix it

  1. Check whether the working environment temperature is too high; turn the inverter off for 10 minutes and restart.
  2. Seek help from Deye if it does not recover.

Source: 081_deye_gb_sl_pro_user_manual_46fa941a.pdf, p.51 · 010_Download_cc05df18.pdf, p.46

Frequently asked questions

What does error 64 mean on a DEYE inverter?
It depends on the model — 12 devices use code 64. On the SUN G01P3-EU-BM8 Series it means: IGBT heat sink high temperature. The card for each model on this page gives its exact meaning and fix.
Is error 64 a fault or a warning?
64 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 64?
1. Check the temperature sensor; check that the firmware is suitable for the hardware and that the inverter is its right model. 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.