These error codes are provided as a reference for the KIWE-KOIE Series system. The list below outlines common indoor unit (IDU) and outdoor unit (ODU) faults as defined in the service manual. Most issues should be inspected and confirmed by a licensed HVAC technician.
Error Code Table
| Code | Reason |
|
E0 |
IDU & ODU Communication failure |
|
E1 |
IDU Room Temperature sensor failure (IDU RT failure) |
|
E2 |
IDU Coil temperature sensor failure (IDU IPT failure) |
|
E3 |
ODU Coil temperature sensor failure (OPT) |
|
E4 |
AC Cooling system abnormal |
|
E5 |
IDU/ODU mismatched failure (especially performance test on the production line) |
|
E6 |
IDU PG Fan motor / DC fan motor works abnormal (IDU failure) |
|
E7 |
ODU Ambient Temperature sensor failure |
|
E8 |
ODU Discharge Temperature sensor failure |
|
E9 |
IPM / Compressor driving control abnormal |
|
EA |
ODU Current Test circuit failure |
|
Eb |
Communication abnormal of Main PCB and Display board (IDU failure) |
|
EE |
ODU EEPROM failure |
|
EF |
ODU DC fan motor failure |
| EH | ODU suction temperature sensor failuture |
|
EU |
ODU Voltage test circuit abnormal |
|
P0 |
IPM module protection |
|
P1 |
Over / under voltage protection |
|
P2 |
Over current protection |
|
P4 |
ODU Discharge pipe over temperature protection |
|
P5 |
Sub-cooling protection on Cooling mode |
|
P6 |
Overheating protection on Cooling mode |
|
P7 |
Overheating protection on Heating mode |
|
P8 |
Outdoor over temperature / under temperature protection |
|
P9 |
Compressor driving protection (Load abnormal) |
|
PA |
Communication failure for TOP flow unit / Preset mode conflict (IDU failure) |
|
F0 |
Infrared customer feeling test sensor failure (IDU failure) |
|
F1 |
Electric power test module failure (IDU failure) |
|
F2 |
Discharge temperature sensor failure protection |
|
F3 |
ODU coil temperature failure protection |
|
F4 |
Cooling system gas flow abnormal |
|
F5 |
PFC protection |
|
F6 |
Compressor lack of phase / anti-phase protection |
|
F7 |
IPM module temperature protection |
|
F8 |
4-Way valve reversing abnormal |
|
F9 |
Module temperature test circuit failure |
|
FA |
Compressor phase-current test circuit failure |
|
Fb |
Limiting/Reducing frequency for overload protection (Cooling/Heating mode) |
|
FC |
Limiting/Reducing frequency for high power consumption protection |
|
FE |
Limiting/Reducing frequency for module current protection (phase current of compressor) |
|
FF |
Limiting/Reducing frequency for module temperature protection |
|
FH |
Limiting/Reducing frequency for compressor driving protection |
|
FP |
Limiting/Reducing frequency for anti-condensation protection |
|
FU |
Limiting/Reducing frequency for anti-frost protection |
|
Fj |
Limiting/Reducing frequency for discharge over temperature protection |
|
Fn |
Limiting/Reducing frequency for ODU AC current protection |
|
Fy |
Gas leakage protection |
|
bf |
TVOC sensor failure (IDU failure, optional) |
|
bc |
PM2.5 sensor failure (IDU failure, optional) |
|
bj |
Humidity sensor failure (IDU failure) |
|
CL |
Filter duty remind |
📄 Need the full technical manual?
Download the complete Error Code & Troubleshooting Guide (PDF) for detailed diagrams and advanced diagnostics.
🔧 COMPLETE TROUBLESHOOTING FLOWS
P0 — IPM Protection
Troubleshooting Flow
Restart unit → Works normally?
→ Yes → End
→ No → Continue
⸻
Check wiring connection (U/V/W)
→ Incorrect → Reconnect
→ P0 disappears?
• Yes → End
• No → Continue
→ Correct → Continue
⸻
Can compressor start?
→ No → Continue
Test voltage between U/V/W–G (DC 20–200V)
→ No voltage → Replace ODU PCB
→ Voltage present → Replace compressor → End
→ Yes → Continue
⸻
Outdoor fan motor slow or not working?
→ Yes → Replace ODU fan motor
→ Works normal?
• Yes → End
• No → Continue
→ No → Continue
⸻
AC pressure correct?
(Cooling: 116–189 psi | Heating: 290–522 psi)
→ No → Continue
Condenser / evaporator dirty?
→ Yes: Clean
→ Unit works?
• Yes → End
• No → Continue
Capillary blocked?
→ Yes: Replace capillary
→ P0 disappears?
• Yes → End
→ Yes → Continue
⸻
Turn unit ON and check again
→ Issue resolved?
• Yes → End
• No → Replace compressor → End
P1 — Over / Under Voltage Protection
Troubleshooting Flow
Power supply between 145–260V?
→ No: Wait until voltage stabilizes
→ P1 disappears?
• Yes → End
• No → Continue
→ Yes → Continue
⸻
Busbar voltage between 150–420V?
→ No: Wait until recovery
→ Unit works?
• Yes → End
• No → Continue
→ Yes → Continue
⸻
Replace ODU PCB → End
P2 — Over Current Protection
Troubleshooting Flow
Indoor fan motor working?
→ No: Replace fan motor
→ P2 disappears?
• Yes → End
• No → Continue
→ Yes → Continue
⸻
Indoor filter or outdoor condenser dirty?
→ Yes: Clean
→ No → Continue
⸻
Restart unit
→ P2 disappears?
• Yes → End
• No → Replace ODU PCB → End
P5 — Sub-Cooling Protection (Cooling/Dry Mode)
Troubleshooting Flow
Wait a few minutes → P5 still displayed?
→ No → Normal → End
→ Yes → Continue
⸻
Indoor filter dirty?
→ Yes: Clean filter
→ P5 disappears?
• Yes → End
• No → Continue
→ No → Continue
⸻
Air inlet blocked?
→ Yes: Clear blockage
→ P5 disappears?
• Yes → End
• No → Continue
→ No → Continue
⸻
Fan blade rotates freely?
→ No: Repair/adjust
→ P5 disappears?
• Yes → End
• No → Continue
→ Yes → Continue
⸻
Fan motor slow or stopped?
→ Yes → Check motor
→ Defective → Replace motor
→ P5 disappears?
• Yes → End
→ No → Continue
⸻
Sensor (IPT) abnormal?
→ Yes: Replace sensor → End
→ No → Replace IDU PCB → End
P6 — Overheating Protection (Cooling Mode)
Troubleshooting Flow
Indoor fan motor working normally?
→ No → Check motor
→ Faulty → Replace
→ P6 disappears?
• Yes → End
→ Yes → Continue
⸻
Sensor loose from connector?
→ Yes: Reconnect
→ P6 disappears?
• Yes → End
• No → Continue
→ No → Continue
⸻
Sensor open or short circuit?
→ Yes: Replace OPT sensor
→ P6 disappears?
• Yes → End
• No → Continue
→ No → Continue
⸻
Replace ODU PCB → End
P7 — Overheating Protection (Heating Mode)
Troubleshooting Flow
Outdoor fan motor working normally?
→ No → Check motor
→ Faulty → Replace
→ P7 disappears?
• Yes → End
→ Yes → Continue
⸻
Sensor loose from connector?
→ Yes: Reconnect
→ P7 disappears?
• Yes → End
• No → Continue
→ No → Continue
⸻
Sensor open or short circuit?
→ Yes: Replace IPT sensor
→ P7 disappears?
• Yes → End
• No → Continue
→ No → Continue
⸻
Replace IDU PCB → End
P8 — Outdoor Over / Under Temperature Protection
Troubleshooting Flow
Ambient temperature within specification?
→ No → Wait until normal
→ Yes → Continue
⸻
Enough space for outdoor ventilation?
→ No: Relocate outdoor unit
→ P8 disappears?
• Yes → End
• No → Continue
→ Yes → Continue
⸻
Sensor open or short circuit?
→ Yes: Replace OAT sensor
→ P8 disappears?
• Yes → End
• No → Continue
→ No → Continue
⸻
Replace ODU PCB → End
P9 — Compressor Driving Protection
Troubleshooting Flow
Compressor wiring (U/V/W) correct?
→ No: Correct wiring
→ Still P9?
• No → End
• Yes → Continue
→ Yes → Continue
⸻
Unit starts < 3 minutes then stops?
→ Yes: Normal protection → Restart after 3 min
→ Still P9?
• No → End
• Yes → Continue
→ No → Continue
⸻
Compressor stops immediately after start?
→ Yes: Replace ODU PCB → End
F4 — Cooling System Gas Flow Abnormal
Check 2-way & 3-way valves open?
→ No: Open valves
→ F4 disappears?
• Yes → End
• No → Continue
→ Yes → Continue
⸻
IPT sensor open or short?
→ Yes: Replace sensor → End
F5 — PFC Protection
F5 appears randomly?
→ Yes: Check power supply
→ Still F5?
• No → End
• Yes → Continue
→ No → Continue
⸻
Turn OFF unit for 3 minutes → Restart
→ Still F5?
• Yes → Replace ODU PCB → End
• No → End
F6 — Compressor Phase Protection
Check wiring → Fix if needed
Check wire condition → Replace if bad
Check phase sequence → Swap wires
Measure resistance (U/V/W)
→ Not equal → Replace compressor
Measure resistance to copper pipe
→ ≤500Ω → Replace compressor
Otherwise → Replace ODU PCB
F7 — Module Temperature Protection
Check IPM contact / screws / dust
Check system pressure & airflow
Check valves / capillary / coils
If unresolved → Replace ODU PCB
F8 — 4-Way Valve Abnormal
Check wiring → Fix
Check voltage → Test coil
Replace coil if faulty
If unresolved → Replace ODU PCB
Fy — Gas Leakage Protection
Check piping for leakage
→ Yes: Repair + recharge
→ Problem solved?
• Yes → End
• No → Replace IDU PCB → End
→ No → Continue
⸻
Check temp difference (RT vs IPT after 10 min)
→ ≤2°C → Continue
Evaporator pipe blocked?
→ Yes: Replace evaporator
→ Problem solved?
• Yes → End
→ >2°C → Continue
⸻
Sensor connected properly?
→ No: Reconnect
Sensor open/short?
→ Yes: Replace
If still issue → Replace IDU PCB → End
CL — Filter Duty Reminder
Check air filter dirty
→ Yes: Clean
Turn OFF and ON power
→ End
