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At TMS Service Center (The Mechanic Squad), we provide a complete and easy-to-understand guide for Air Conditioner (AC) error codes of all major brands, along with professional AC repair services across Chennai. If your AC is showing an error code on the display panel or blinking LED lights, this page will help you understand what the code means and what may be causing the issue. Modern split and inverter air conditioners display specific error codes when there is a temperature sensor fault, communication problem, refrigerant leakage, compressor malfunction, inverter PCB failure, pressure protection activation, voltage abnormality, or fan motor error.
Whether you are searching for LG AC error codes, Samsung AC error codes, Daikin AC error codes, Voltas AC error codes, Blue Star AC error codes, Hitachi AC error codes, Carrier AC error codes, Panasonic AC error codes, Mitsubishi AC error codes, O General AC error codes, Toshiba AC error codes, Whirlpool AC error codes, Lloyd AC error codes, Haier AC error codes, IFB AC error codes, Godrej AC error codes, Voltas Beko AC error codes, or Onida AC error codes, you can find brand-wise explanations below to identify the issue clearly.
Each error code listed on this page includes a short and simple explanation so you can understand whether the issue is minor or requires immediate technical attention. While some codes indicate normal protection modes such as defrost operation, others signal serious problems like compressor overload, inverter module fault, or refrigerant shortage.
If your AC continues to display an error code, does not cool properly, or shuts down repeatedly, it is recommended to avoid repeated restart attempts and seek expert diagnosis. At TMS Service Center, we not only help you understand AC error codes but also provide trusted AC repair services in Chennai with just ₹99 inspection charge and 6-month service warranty, ensuring transparent pricing, genuine spare parts, and long-lasting repair solutions for all leading air conditioner brands.
Browse the brand-wise AC error codes below to find the specific code displayed on your unit.
Facing AC error codes like E1 (Sensor Error), E2 (Evaporator Sensor Fault), E3 (Low Pressure Error), E4 (High Temperature Error), P1 (Voltage Protection), F1/F3 (Indoor/Outdoor Sensor Fault), H3 (Compressor Overload), EC (Refrigerant Leakage Error), U4 (Communication Error), or CH Codes (Brand-Specific Faults)? Don’t worry — we diagnose and fix them quickly with accurate testing and professional tools.
Our expert AC technicians in Chennai specialize in repairing all major air conditioner brands including LG, Samsung, Daikin, Voltas, Blue Star, Hitachi, Panasonic, Whirlpool, Godrej, Haier, Carrier, Toshiba, Mitsubishi Electric, Mitsubishi Heavy Industries, O General, Onida, Lloyd, IFB, Videocon, Kelvinator, Sharp, Sansui, Trane, Fujitsu, York, Hisense, TCL, General, Aux, Midea, Sanyo, Akai, Crompton, Intex, and more, ensuring reliable doorstep AC repair service at affordable rates.
CH01 / CH1 – Indoor room temperature sensor fault.
CH02 / CH2 – Indoor pipe (coil) temperature sensor fault.
CH03 / CH3 – Communication error between indoor and outdoor unit.
CH04 / CH4 – Drain pump malfunction or water overflow detected.
CH05 / CH5 – Indoor and outdoor communication failure.
CH06 / CH6 – Indoor coil temperature sensor error.
CH07 / CH7 – Operation mode mismatch (multi-split models).
CH09 / CH9 – Indoor fan motor fault.
CH10 / CH10 – Indoor fan motor lock or abnormal speed.
CH21 – Outdoor inverter compressor overcurrent error.
CH22 – Outdoor unit current overload protection activated.
CH23 – DC link low voltage error.
CH24 – Low / high pressure switch error.
CH26 – Inverter compressor startup failure.
CH27 – Power supply circuit (PSC) fault.
CH29 – Compressor overcurrent protection triggered.
CH32 – High discharge temperature error.
CH33 – Discharge pipe overheat error.
CH34 – High pressure protection activated.
CH35 – Low pressure protection activated.
CH36 – Refrigerant leakage detected.
CH38 – Low refrigerant level warning.
CH39 – Outdoor PCB communication fault.
CH40 – Current Transformer (CT) sensor error.
CH41 – Outdoor discharge temperature sensor fault.
CH44 – Outdoor air temperature sensor error.
CH45 – Outdoor condenser temperature sensor fault.
CH47 – Outdoor pipe temperature sensor error.
CH48 – Outdoor heat sink temperature sensor error.
CH51 – Capacity mismatch between indoor and outdoor unit.
CH53 – Main PCB and sub PCB communication error.
CH54 – Power phase detection error.
CH60 – EEPROM memory error.
CH61 – Outdoor heat sink overheating.
CH62 – Outdoor inverter PCB heat sink sensor error.
CH65 – Heat sink temperature sensor open/short circuit.
CH67 – BLDC outdoor fan motor lock error.
E101 – Indoor and outdoor unit communication error.
E102 – Outdoor unit communication fault.
E121 – Indoor room temperature sensor error.
E122 – Indoor coil temperature sensor fault.
E154 – Indoor fan motor malfunction.
E161 – EEPROM memory error (indoor PCB).
E163 – Option setting error.
E164 – EEPROM write/read error.
E201 – Outdoor unit communication error.
E202 – Indoor and outdoor tracking error.
E221 – Outdoor temperature sensor fault.
E231 – Outdoor condenser temperature sensor error.
E241 – Outdoor discharge temperature sensor fault.
E251 – Outdoor current sensor error.
E256 – Compressor rotation error.
E301 – Drain pump error (water overflow).
E302 – Drain sensor malfunction.
E416 – High temperature protection activated.
E422 – Low pressure protection error.
E441 – High pressure protection error.
E442 – Refrigerant leakage detected.
E443 – Outdoor unit overheat protection.
E461 – Outdoor inverter compressor drive error.
E462 – Inverter current protection triggered.
E463 – DC link voltage error.
E464 – IPM (Intelligent Power Module) overheating.
E465 – Compressor startup failure.
E554 – Capacity mismatch between indoor and outdoor unit.
E556 – Indoor fan motor lock.
CF – Filter cleaning reminder (not a fault, maintenance alert).
dF – Defrost mode active (normal operation).
A1 – Indoor PCB malfunction.
A3 – Drain system malfunction (water overflow).
A5 – Freeze protection activated (indoor heat exchanger).
A6 – Indoor fan motor fault.
A9 – Electronic expansion valve error.
C4 – Indoor heat exchanger temperature sensor fault.
C5 – Indoor pipe temperature sensor error.
C9 – Indoor room temperature sensor malfunction.
E1 – Outdoor PCB malfunction.
E3 – High pressure protection activated.
E4 – Low pressure protection activated.
E5 – Outdoor unit overload protection.
E6 – Outdoor fan motor error.
E7 – Outdoor DC fan motor fault.
E8 – Outdoor overcurrent protection.
E9 – Electronic expansion valve error (outdoor).
EA – 4-way valve switching error (heat pump models).
F3 – Discharge pipe high temperature error.
F6 – Outdoor heat exchanger temperature error.
H0 – Sensor fault (general sensor malfunction).
H6 – Compressor motor position detection error.
H8 – Outdoor CT (current transformer) sensor error.
H9 – Outdoor air temperature sensor fault.
J3 – Discharge pipe temperature sensor error.
J6 – Outdoor heat exchanger sensor fault.
J7 – Outdoor pipe temperature sensor malfunction.
L3 – Electrical box temperature rise error.
L4 – Inverter heat sink overheat error.
L5 – Inverter compressor overcurrent error.
L8 – Inverter compressor electrical fault.
P1 – Power supply voltage abnormal.
P3 – Compressor discharge temperature abnormal.
P4 – Heat sink temperature high.
U0 – Refrigerant shortage detected.
U2 – Power supply voltage error.
U4 – Communication error between indoor and outdoor unit.
U7 – Outdoor to outdoor communication error (multi system).
E0 – Indoor and outdoor communication error.
E1 – Indoor room temperature sensor fault.
E2 – Indoor coil temperature sensor error.
E3 – Indoor fan motor malfunction.
E4 – Indoor EEPROM memory error.
E5 – Indoor unit overload protection activated.
E6 – Outdoor temperature sensor fault.
E7 – Outdoor coil temperature sensor error.
E8 – Outdoor fan motor malfunction.
E9 – Outdoor unit communication fault.
F0 – Refrigerant leakage detected or low gas condition.
F1 – Indoor ambient temperature sensor error.
F2 – Indoor pipe temperature sensor fault.
F3 – Compressor discharge temperature high.
F4 – Outdoor condenser temperature sensor fault.
F5 – Outdoor heat exchanger temperature error.
H3 – Compressor overload protection activated.
H5 – Inverter module protection error.
H6 – Indoor fan motor lock.
H7 – Outdoor fan motor lock.
P0 – Inverter module protection activated.
P1 – Voltage protection (high/low voltage).
P2 – Compressor top temperature protection.
P4 – Inverter compressor drive error.
P5 – Outdoor condenser high temperature protection.
L3 – Outdoor electrical box overheating.
L8 – Inverter compressor malfunction.
dF – Defrost mode active (normal operation, not a fault).
01 – Indoor room temperature sensor fault.
02 – Indoor pipe temperature sensor error.
03 – Indoor heat exchanger temperature sensor fault.
04 – Outdoor ambient temperature sensor error.
05 – Outdoor condenser temperature sensor fault.
06 – Outdoor discharge temperature sensor error.
07 – Communication failure between indoor and outdoor unit.
08 – Serial communication error.
09 – Indoor PCB communication malfunction.
11 – Indoor fan motor fault.
12 – Indoor fan motor lock error.
13 – Outdoor fan motor malfunction.
14 – Outdoor fan motor lock error.
21 – Compressor overcurrent protection activated.
22 – Compressor motor position detection error.
23 – Inverter module overcurrent protection.
24 – Inverter heat sink overheat error.
25 – Compressor discharge temperature high.
26 – Compressor startup failure.
27 – IPM (Inverter Power Module) protection activated.
31 – High pressure protection activated.
32 – Low pressure protection activated.
33 – Refrigerant leakage detected.
34 – Low refrigerant level warning.
41 – Voltage abnormal (high/low voltage).
42 – Outdoor overcurrent protection.
43 – Electrical box overheating.
44 – Power supply phase detection error.
51 – EEPROM memory error (Indoor PCB).
52 – EEPROM memory error (Outdoor PCB).
53 – Indoor PCB malfunction.
54 – Outdoor PCB malfunction.
61 – Defrost mode active (normal operation).
62 – Anti-freeze protection activated.
63 – Capacity mismatch error.
64 – Mode mismatch error (multi-split systems).
E0 – Indoor and outdoor communication error.
E1 – Indoor room temperature sensor fault.
E2 – Indoor coil temperature sensor error.
E3 – Indoor fan motor malfunction.
E4 – Indoor EEPROM memory error.
E5 – Indoor unit overload protection activated.
E6 – Outdoor temperature sensor fault.
E7 – Outdoor coil temperature sensor error.
E8 – Outdoor fan motor malfunction.
E9 – Outdoor communication error.
F0 – Refrigerant leakage detected or low gas condition.
F1 – Indoor ambient temperature sensor error.
F2 – Indoor pipe temperature sensor fault.
F3 – Compressor discharge temperature high.
F4 – Outdoor condenser temperature sensor fault.
F5 – Outdoor heat exchanger temperature error.
H3 – Compressor overload protection activated.
H5 – Inverter module protection error.
H6 – Indoor fan motor lock.
H7 – Outdoor fan motor lock.
P0 – Inverter module protection activated.
P1 – Voltage protection (high/low voltage).
P2 – Compressor top temperature protection.
P4 – Inverter compressor drive error.
P5 – Outdoor condenser high temperature protection.
L3 – Outdoor electrical box overheating.
L8 – Inverter compressor malfunction.
dF – Defrost mode active (normal operation, not a fault).
P1 – Indoor room temperature sensor fault.
P2 – Indoor pipe temperature sensor error.
P4 – Indoor drain pump malfunction or water overflow detected.
P5 – Indoor heat exchanger temperature abnormal.
P6 – Freeze protection activated.
P8 – Indoor coil temperature abnormal.
E1 – Indoor and outdoor communication error.
E3 – High pressure protection activated.
E4 – Low pressure protection activated.
E5 – Outdoor unit overload protection.
E6 – Outdoor fan motor malfunction.
E7 – Outdoor DC fan motor fault.
E8 – Outdoor overcurrent protection.
E9 – Electronic expansion valve error.
F3 – Compressor discharge temperature high.
F6 – Outdoor heat exchanger temperature error.
F8 – Outdoor electrical box overheating.
H0 – Sensor fault detected.
H1 – Compressor motor abnormality.
H3 – Compressor overcurrent protection.
H5 – Inverter module protection activated.
H6 – Indoor fan motor lock error.
U0 – Refrigerant shortage detected.
U1 – Power supply phase error.
U2 – Voltage abnormal (high/low voltage).
U4 – Communication error between indoor and outdoor unit.
U8 – Outdoor to outdoor communication error (multi system).
dF – Defrost mode active (normal operation, not a fault).
E01 – Indoor and outdoor communication error.
E02 – Indoor room temperature sensor fault.
E03 – Indoor coil (pipe) temperature sensor error.
E04 – Indoor fan motor malfunction.
E05 – Indoor EEPROM memory error.
E06 – Outdoor ambient temperature sensor fault.
E07 – Outdoor condenser temperature sensor error.
E08 – Outdoor fan motor malfunction.
E09 – Outdoor unit communication failure.
E10 – Indoor PCB malfunction.
F0 – Refrigerant leakage detected or low gas condition.
F1 – Indoor ambient temperature sensor error.
F2 – Indoor pipe temperature sensor fault.
F3 – Compressor discharge temperature high.
F4 – Outdoor heat exchanger temperature sensor fault.
F5 – Outdoor condenser overheat protection activated.
H3 – Compressor overload protection activated.
H5 – Inverter module protection error.
H6 – Indoor fan motor lock error.
H7 – Outdoor fan motor lock error.
P0 – Inverter module protection fault.
P1 – Voltage abnormal (high/low voltage).
P2 – Compressor top temperature protection.
P4 – Inverter compressor drive error.
P5 – Outdoor high temperature protection.
L3 – Outdoor electrical box overheating.
L8 – Inverter compressor malfunction.
dF – Defrost mode active (normal operation, not a fault).
E0 – Indoor and outdoor communication error.
E1 – Indoor room temperature sensor fault.
E2 – Indoor coil (pipe) temperature sensor error.
E3 – Indoor fan motor malfunction.
E4 – Indoor EEPROM memory error.
E5 – Indoor unit overload protection activated.
E6 – Outdoor ambient temperature sensor fault.
E7 – Outdoor condenser temperature sensor error.
E8 – Outdoor fan motor malfunction.
E9 – Outdoor communication failure.
F0 – Refrigerant leakage detected or low gas condition.
F1 – Indoor ambient temperature sensor error.
F2 – Indoor pipe temperature sensor fault.
F3 – Compressor discharge temperature high.
F4 – Outdoor heat exchanger temperature sensor fault.
F5 – Outdoor condenser overheat protection activated.
H3 – Compressor overload protection activated.
H5 – Inverter module protection error.
H6 – Indoor fan motor lock error.
H7 – Outdoor fan motor lock error.
P0 – Inverter module protection fault.
P1 – Voltage abnormal (high/low voltage).
P2 – Compressor top temperature protection.
P4 – Inverter compressor drive error.
P5 – Outdoor high temperature protection.
L3 – Outdoor electrical box overheating.
L8 – Inverter compressor malfunction.
dF – Defrost mode active (normal operation).
Yes, The Mechanic Squad (TMS) offers same-day doorstep Air Conditioner (AC) service within 90 minutes
It’s a technician visit fee, fully waived if you proceed with the repair.
We handle All Makes & Models Split Air Conditioner (AC), Non Inverter Air Conditioner (AC) & Inverter Air Conditioner (AC).
We provide expert repair and service support for all major brands including LG, Samsung, Daikin, Voltas, Blue Star, Hitachi, Panasonic, Whirlpool, Godrej, Haier, Carrier, Toshiba, Mitsubishi Electric, Mitsubishi Heavy Industries, O General, Onida, Lloyd, IFB, Videocon, Kelvinator, Sharp, Sansui, Croma, Amazon Basics, Mitashi, BPL, Electrolux, General, AUX, Hisense, Sanyo, Akai, Intex, TCL, Hyundai, Micromax, Vestar, Super General, Cruise, Napoleon, Koryo, MarQ (Flipkart), Realme TechLife, Xiaomi (Mi AC), OnePlus AC and more — covering all latest and old models across Chennai and Tamil Nadu.
Yes, 6-Month warranty is provided on all service and spares.
“Excellent AC service. My split AC was not cooling properly and the technician fixed the gas leakage issue quickly. Very professional and clean work.”
Raja , Tambaram
“Booked AC repair for my LG inverter AC. They identified the PCB issue within minutes and explained everything clearly before repair. Totally satisfied.”
Sathish Kumar, Vdapalani
“My window AC had water leakage problem. TMS team came same day and resolved it at affordable cost. Cooling is perfect now.”
Jenifer, T.Nagar
“Very happy with their AC servicing. Complete cleaning and maintenance done properly. Technician was polite and experienced.”
Shanmugam, Selaiyur
“Compressor issue in my Daikin AC was fixed professionally. Transparent pricing and only ₹99 inspection charge. Highly recommended AC service in Chennai.”
Sheela, Ramapuram
These reviews are from real customers who have chosen TMS Service Center for fast and reliable Air Conditioner (AC) service in Chennai.
TMS Service Center (The Mechanic Squad) provides trusted AC repair services across Chennai, Coimbatore, Madurai, Chennai, Trichy, Salem, Erode, Tirunelveli, Vellore, Thanjavur, Hosur, and major cities throughout Tamil Nadu. We specialize in split AC, window AC, inverter AC, and non-inverter air conditioner repair services with professional doorstep support. We also offer AC gas refilling, installation, uninstallation, PCB repair, and preventive maintenance services across Tamil Nadu with just ₹99 inspection charge and same-day service support.
📞Book Your Air Conditioner (AC) Repair Services in Tamil Nadu Today – Call TMS Service Center Now for ₹99 Inspection & Same-Day Service!
If You Need To learn Appliances Mechanic Course And AC PCB Repairing Course Please Visit “Chennai Excellent Center For Vocational Training” ( CECVT )
If You Need Appliances Spare Parts Please Visit SKM Enterprises
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