Your Haier aircon is showing an error code like E06, E21, or E40 on the indoor controller, and you need to know what it means. You need three things: how to read the code on your Haier display, what each code actually represents, and whether you can fix it yourself or need to call a technician.
This guide answers all three. At Lion City Aircon, we’ve serviced over 22,000 aircon units across Singapore since 2016, including Haier residential splits and multi-split systems. This page is based on Haier’s official service documentation cross-checked against what we actually see in real Singapore homes.
Jump to your section:
- How to Read Your Haier Error Code
- Indoor Unit Codes (E01-E20)
- Outdoor Unit Codes (E20-E124)
- Repair Cost in Singapore
- Frequently Asked Questions
How to Read Your Haier Error Code
Haier aircons display error codes on the wired controller, the indoor unit display panel, or via flashing LED patterns on the indoor unit. The system distinguishes between indoor unit faults (codes 01 to 20) and outdoor unit faults (codes 20 onwards, including sub-coded faults like E20-0, E20-1).
Wired Controller Display
On wired Haier controllers:
- When a fault is active, the error code appears directly on the controller’s LCD display.
- Codes show in the format “E01” through “E124” plus sub-codes (e.g., E20-0, E51-2).
- Some Haier controllers also store fault history. Press the menu or check button to recall recent faults.
Indoor Unit Display Panel
On models with a built-in display panel on the indoor unit, the code appears directly on the panel as a 2 or 3 digit number.
LED Flash Pattern (Wireless Remote Models)
For models without a digital display, count the LED flashes on the indoor unit during a fault condition. Each flash sequence corresponds to a code in the table below.
If You Can’t Read the Code Clearly
- Take a photo of the wired controller or indoor unit display.
- If the code is intermittent or the LEDs are flashing, take a 30-second video.
- WhatsApp +65 8818 5781. We can identify the code and likely cause before sending a team.
Understanding “Resumable” vs “Unresumable” Faults
Haier’s documentation classifies faults two ways:
- Resumable: the fault clears automatically once normal operating conditions are restored (sensor reconnected, pressure returns to normal, communication restored).
- Unresumable: the fault is locked in until manually cleared or the underlying component is replaced. These are typically EEPROM faults, hardware overcurrent events, or “confirmed” protection trips that occurred 3 times in an hour.
Indoor Unit Errors (E01 to E20)
E01: Water Inlet Temperature Sensor Abnormality
The thermistor reading water inlet temperature (on hydro split or hybrid models) has disconnected or shorted. The AD value is below 11 (open circuit) or over 1012 (short circuit) for 60 seconds. Severity: Medium. Resumable once the sensor connection is restored. Replacement runs from $130.
E02: Water Outlet Temperature Sensor (Two/Tout2) Abnormality
Same as E01 but for the water outlet sensor. Medium severity. Resumable. Same fix pattern.
E03: Liquid Pipe Temperature Sensor Abnormality
The thermistor on the liquid refrigerant pipe has failed. Medium severity. Resumable. Common thermistor replacement.
E04: Gas Pipe Temperature Sensor Abnormality
The thermistor on the gas refrigerant pipe has failed. Medium severity. Resumable.
E05: EEPROM Abnormality
The indoor unit’s EEPROM check has failed. High severity. Unresumable. Causes: faulty EEPROM, incorrect dip switch setting on the indoor main PCB. Often requires indoor PCB replacement. $250 to $450.
E06: Communication Error Between Outdoor Unit and Indoor Unit
The indoor unit can’t receive communication signals from the outdoor unit for 2 consecutive minutes. One of the most common Haier codes we attend in Singapore. High severity. Resumable. Causes: outdoor unit power off, damaged communication cable, wrong dip switch settings, failed PCB on either end. First check: is the outdoor unit isolator switched on?
E07: Communication Error Between Wired Controller and Indoor Unit
The wired controller hasn’t received valid data for 4 consecutive minutes. Medium severity. Resumable. Causes: damaged controller cable, loose connection, defective wired controller, or PCB fault.
E08: Flow Switch Abnormality / Low Water Flow
For hydro split models. The water pump has been operating for 120 seconds without a water flow signal. Medium severity. Resumable. Common causes: blocked filter, water pump rotor seized (especially after extended shutdown over half a year), low water level, or failed flow switch. If E08 occurs 3 times in an hour, the failure is confirmed.
E09: Indoor Unit Address Duplication Abnormality
Two or more indoor units in a multi-system have the same address. High severity. Resumable. Configuration issue, usually after installation or unit replacement. Needs technician to correct DIP switch settings.
E10: DHW Tank Temperature Sensor Abnormality
For models with domestic hot water (DHW) function. The water tank temperature sensor has failed. Medium severity. Resumable.
E11: I/O PCB Communication Abnormality
The I/O board signal cannot be received for 2 minutes. High severity. Resumable. Check communication cable between I/O board and main PCB.
E12: ZONE2 Water Mixing Valve Temperature Sensor Abnormality
Sensor fault on the secondary zone mixing valve. Medium severity. Resumable. Sensor replacement.
E13: Water Leakage Detected
The water leak detection switch has closed for 60 seconds. High severity. Unresumable. Switch off immediately and investigate the leak source. Common in hydro split installations where water plumbing has compromised seals.
E14: Low Pressure Switch Abnormality (Reserved)
The low pressure switch has disconnected for 5 seconds. High severity. Resumable. Common in flow-restricted systems or refrigerant shortage scenarios.
E15: Anti-freeze Abnormality
In cooling mode, the water temperature has dropped below 3°C or temperature differential conditions indicate freezing risk. Medium severity. Resumable. Causes: low water flow (often related to E08), incorrectly positioned sensors, or refrigerant issues. If E15 occurs 3 times in an hour, failure is confirmed.
E16: Water Inlet/Outlet Temperature Over High
Water temperature has exceeded 82°C for 5 seconds. High severity. Resumable. Causes: auxiliary electric heater on inappropriately, defective sensor, or program version issue.
E17: ZONE1 Ambient Temperature Sensor Abnormality
The ambient temperature sensor for zone 1 has failed. Medium severity. Resumable.
E18: ZONE2 Ambient Temperature Sensor Abnormality
Same as E17 but for zone 2.
E19: Pool Mixing Valve / Pool Water Temperature Sensor
Sensor fault for pool heating models. Medium severity. Resumable. Less common in Singapore HDB or condo installations.
E20: Outdoor Unit Abnormality
General outdoor unit fault. Usually accompanied by a more specific E20-x sub-code from the outdoor unit. See outdoor codes section below.
Outdoor Unit Errors (E20 to E124)
E20-0, E20-1: Outdoor Condenser Defrosting Coil Sensors
The Te1 or Te2 sensors on the outdoor condenser coil have failed. Medium severity. Resumable. Sensor replacement.
E21: Outdoor Ambient Temperature Sensor Abnormality
The outdoor air temperature sensor has failed. Medium severity. Resumable. Cheap fix.
E22: Compressor Suction Temperature Sensor Abnormality
The suction temperature sensor has failed. Medium severity. Resumable. Sensor replacement.
E23: Compressor Discharge Temperature Sensor Abnormality
The discharge temperature sensor has failed. Medium severity. Resumable. Important sensor because it protects against compressor overheating.
E24: Compressor Oil Temperature Sensor Abnormality
The oil temperature sensor has failed. Medium severity. Resumable.
E27: Oil Temperature Over High Protection
Compressor oil temperature has exceeded 110°C. High severity. Once confirmed, unresumable. Don’t continue running the unit. Compressor risk.
E28: Compressor Discharge Pressure Sensor Abnormality
The high pressure sensor has failed. Medium severity. Resumable. Sensor replacement.
E29: Compressor Suction Pressure Sensor Abnormality
The low pressure sensor has failed. Medium severity. Resumable.
E30: High Pressure Switch HPS Abnormality
The high pressure switch has tripped. High severity. Once confirmed, unresumable. Causes: dirty outdoor unit (Singapore’s #1 cause), refrigerant overcharge, system blockage, failed switch.
E32-0, E32-1: Subcooling and Liquid Pipe Temperature Sensors
Outdoor subcooling coil or liquid pipe sensor failure. Medium severity. Resumable.
E33: Outdoor Unit PCB EEPROM Abnormality
Outdoor EEPROM communication failure. High severity. Unresumable. Outdoor PCB replacement typically needed. $300 to $600.
E34: Compressor Discharge Temperature Over High Protection
Discharge temperature exceeded 115°C. High severity. Once confirmed, unresumable. Most common cause: low refrigerant (the compressor runs hotter without enough gas to absorb heat). Other causes: restricted flow, expansion valve issues, defective discharge sensor.
E35: Four Way Valve Reversing Abnormality
The 4-way reversing valve isn’t operating correctly. High severity. Once confirmed, unresumable. Less common in Singapore where cool-only operation dominates.
E36: Oil Temperature Over Low Protection
Oil temperature too low for safe operation. High severity. Once confirmed, unresumable.
E38: High Pressure Over Low Protection
High pressure side reading has dropped abnormally low. High severity. Once confirmed, unresumable. Often indicates refrigerant shortage or expansion valve issues.
E39-0, E39-1: Low Pressure / Compression Ratio Protection
Low pressure has dropped too low (cooling: below 5.8kg; heating: below 0.3kg) or compression ratio exceeded 10.0. High severity. Once confirmed, unresumable. Refrigerant leak likely.
E40: High Pressure Over High Protection
System high pressure has exceeded 41.5kg. High severity. Once confirmed, unresumable. Causes: refrigerant overcharge, dirty outdoor condenser, blocked piping system, blocked airflow. Switch off immediately.
E43: Discharge Temperature Over Low Protection
Discharge temperature unusually low during normal operation. High severity. Once confirmed, unresumable. Often indicates refrigerant overcharge or expansion valve stuck open.
E46: Communication Error with Driver PCB
The main PCB cannot communicate with the inverter driver board for 30 seconds. High severity. Resumable. Check cable between main PCB and driver PCB.
E49: Low Pressure Switch Abnormality
Low pressure switch disconnected for 5 seconds. High severity. Once confirmed, unresumable.
E51-0, E51-2: LEV Overcurrent Protection
Electronic expansion valve (LEV) driver chip has detected overcurrent. Medium severity. Resumable. LEV coil or driver issue.
E52-0, E52-2: LEV Disconnection Abnormality
LEV driver chip cannot detect the valve coil connection. Medium severity. Resumable.
E53: CT Current Over Low / Current Sensor Abnormality
Compressor current sensor reading is abnormally low. Medium severity. Resumable. Diagnostic required.
E54 to E63: Subcooling Module Errors
Various subcooling module faults (communication, sensor, DIP switch errors). Mostly resumable. Specialised diagnosis needed; typically commercial installations.
E64: CT Current Over High
Current transformer reading exceeded specified value for 5 seconds. High severity. Once confirmed, unresumable. Causes: compressor overload, refrigerant overcharge, mechanical wear.
E65: Electrical Control Box Temperature Sensor (Tb) Abnormality
Control box thermistor failure. Medium severity. Resumable.
E68: Communication Error with DHW I/O PCB
DHW (hot water) board communication failure for 2 minutes. High severity. Resumable.
E69: DHW I/O PCB Tank Temperature Abnormality
Tank temperature sensor on DHW board has failed. Medium severity. Resumable.
E71-0, E71-1: DC Fan Motor Abnormality
Upper or lower DC fan motor on outdoor unit running below 20 rpm or below 20% of target. High severity. Once confirmed, unresumable. Fan motor replacement runs $200 to $350.
E74: System Emergency Stop Abnormality
External interface has triggered emergency stop. High severity. Resumable. Check connected external systems.
E81: Compressor Driver PCB Temperature Over High Protection
Inverter module temperature exceeded 85°C. High severity. Once confirmed, unresumable. Causes: poor outdoor unit ventilation, dust on heat sink, ambient temperature too high.
E82: Compressor Current Protection
Variable frequency compressor current exceeded specified value. High severity. Once confirmed, unresumable.
E83: Incorrect Outdoor Unit DIP Switch Setting
Outdoor model DIP switches don’t match the master configuration. High severity. Unresumable. Technician must correct the DIP settings.
E87: Defrosting with Over Low Water Temperature
Water temperature dropped too low during defrost cycle. Medium severity. Resumable. Affects hydro split heat pump models in heating operation.
E110: Compressor Hardware Overcurrent
Hardware-detected compressor overcurrent event. High severity. Unresumable after 4 occurrences in an hour. Inverter PCB diagnosis required.
E111: Compressor / Fan Motor Loss of Synchronism
Rotor angle error during compressor or fan motor operation. Severity varies. Resumable for fan motor (30 second hold), high severity for compressor.
E112: Driver PCB Heat Sink Temperature Over High
Heat sink temperature exceeded 95°C for 5 seconds. High severity. Resumable. Auto-resumes when temperature drops below 80°C. Check ventilation and heat sink cleanliness.
E114: Inverter Input Power Supply Voltage Abnormal
DC BUS voltage either below 160V or above 430V. High severity. Resumable. Supply voltage issue. Electrician verification needed.
E116: Communication Error Between Compressor Driver PCB and Main PCB
Communication signal not detected for 30 seconds. High severity. Resumable. Auto-resumes when signal restored.
E117: Compressor Software Overcurrent
Software-detected compressor overcurrent. High severity. Resumable. Often indicates compressor overload or PCB fault.
E118: Compressor Start-up Abnormality
Compressor failed to start 5 times in a row. High severity. Resumable. Causes: compressor mechanical issue, low supply voltage, refrigerant pressure imbalance at startup.
E119: Compressor Driver PCB Current Detect Circuit Abnormality
Current detection circuit fault. High severity. Resumable. Inverter PCB replacement typical.
E121: Compressor Control Board Power Supply Abnormality
Module control board power supply has broken down. High severity. Resumable.
E122: Compressor Driver PCB Heat Sink Temperature Sensor Abnormality
Heat sink temperature sensor failure. High severity. Resumable.
E124: Compressor Driver PCB Three-Phase Power Supply Abnormality
Module three-phase power failure (commercial/3-phase models). High severity. Resumable. Electrician check needed.
What to Do When You See a Haier Error Code
- Note the exact code displayed (including any sub-code like E20-0 or E51-2).
- Check whether it’s resumable or unresumable using the descriptions above.
- For Medium severity sensor codes (E01-E04, E10, E17-E19, E20-x, E21-E24, E28-E29, E32-x, E65, E69): book a service within the next few days. The unit may still run but is degraded.
- For High severity codes (E27, E30, E34, E40, E64, E71-x, E81-E82, E110-E124): switch off the aircon and call a technician. Compressor or inverter damage risk if you continue running.
- For E06, E07, E08 (communication and flow): first verify the outdoor unit isolator is on and check terminal connections.
- For E13 (water leakage): switch off immediately. Investigate the leak source before restarting.
- WhatsApp +65 8818 5781 with a photo of the code and outdoor unit nameplate. We’ll identify the cause before sending a team.
How Much Does Fixing a Haier Error Code Cost in Singapore?
Lion City Aircon pricing across Singapore (HDB, condo, landed, same rate):
- Diagnostic visit: $35 to $50 per unit
- Thermistor replacement (sensor faults: E01-E04, E10, E17-E24, E28-E29, E32-x, E65, E69): from $130 (parts and labour)
- EEPROM replacement (E05, E33): from $130
- Capacitor replacement: from $130
- Fan motor replacement (E71-0, E71-1): $200 to $350
- LEV (expansion valve) replacement (E51-x, E52-x): $300 to $500
- Indoor PCB replacement: $250 to $450
- Outdoor PCB or inverter PCB replacement (E33, E110-E124): $300 to $600
- Gas leak repair plus recharge (E34, E38, E39-x, E40): from $180
- Water pump replacement (E08 on hydro models): from $250
- Compressor replacement (E27, E82, E118): from $750
If you’re on our annual maintenance contract, diagnostic visits are free and most thermistor and capacitor replacements are included between scheduled visits.
Frequently Asked Questions About Haier Error Codes
What’s the most common Haier error code in Singapore?
E06 (indoor-outdoor communication) is the most common, followed by E30 (high pressure switch from dirty outdoor unit) and E34 (high discharge temperature from low refrigerant). All are diagnosable in a single visit.
What does “resumable” mean for a Haier error code?
A resumable code clears automatically when normal operating conditions return. For example, E06 (communication) is resumable: if the outdoor unit power was off and you turn it back on, the code clears. An unresumable code stays locked until manually cleared or the underlying component is replaced. EEPROM faults (E05, E33) are typical unresumable codes.
Why does my Haier show “E20” without a sub-code?
E20 alone is a general outdoor unit fault indicator. The specific outdoor sub-code (E20-0, E20-1, E21, E22, etc.) tells you what’s actually wrong. If your display only shows E20, check the outdoor unit’s own display or wired controller for the sub-code.
Can I clear a Haier error code by switching off the aircon?
Resumable codes often clear with a full power reset if the underlying cause was transient. Unresumable codes won’t clear because the underlying fault is permanent until repaired (sensor replaced, PCB swapped, refrigerant recharged). Don’t ignore returning codes.
What does the “3 times in an hour” rule mean?
Several Haier protection codes (E08, E15, E27, E30, E34, E36, E38, E39-x, E40, E43, E49, E64, E71-x, E81, E82) follow this rule: if the protection trip occurs 3 times within an hour, the failure is “confirmed” and the unit locks out until manually reset by a technician. This prevents continuous restart attempts that could damage components.
My Haier hydro split shows E08 after I just installed it. What do I do?
E08 (low water flow) on first installation often means the water pump rotor has crystallised from extended shutdown. Haier’s documentation requires specific procedures: power off the unit, manually rotate the pump rotor to free it, then restart. If the pump still doesn’t operate after rotation, the pump needs replacement. For pure aircon (not hydro) models, E08 doesn’t apply.
Should I try to fix Haier codes myself?
Filter cleaning, basic visual inspection, and power resets are safe DIY. Anything involving refrigerant (E30, E34, E38-E40), inverter components (E110-E124), water plumbing (E08, E13), or PCB replacement needs a licensed technician. Refrigerant handling is regulated in Singapore.
Are Haier codes the same on all models in Singapore?
The core E01-E124 code system is consistent across Haier residential splits, multi-splits, and hydro split heat pump models. Some hydro-specific codes (E08, E13, E14, E16, E87) only apply to water heating models. Pure air conditioning models in Singapore homes use the air-related codes (E01-E07, E20 and outdoor codes onwards).
How long does fixing a Haier error code take?
Most diagnoses take 30 to 45 minutes. Sensor replacements add 30 minutes. PCB or fan motor replacements take 60 to 90 minutes. Compressor replacement takes 2 to 3 hours. We carry common parts on the truck, so most fixes are complete in a single visit.
Get Your Haier Aircon Fixed Today
Most Haier error codes are diagnosable in a single visit. The longer you wait with an active fault, the more likely cascading damage develops, especially with unresumable compressor or inverter codes (E27, E30, E34, E40, E64, E71-x, E81-E82, E110-E124).
WhatsApp +65 8818 5781 with a photo of the error code and your outdoor unit nameplate. We diagnose remotely where possible and dispatch a team. Same-day service in most cases across Singapore. 22,000+ jobs done since 2016, 5.0★ across 1,500+ Google reviews, BizSafe Level 3 certified.
No scare tactics. No upselling. If your fix is a $130 sensor, we’ll tell you that and price it accordingly. If it’s a serious inverter or compressor issue, we’ll show you what we found and give you honest repair-versus-replace numbers before doing anything.
WhatsApp Lion City Aircon · Call +65 8818 5781 · Book online
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