Updated July 2026 · By Singapore Aircond Service Centre
When your aircon stops and flashes a code, that code tells you exactly where to look — if you know how to read it. This reference covers the most common error codes for the five biggest aircon brands in Singapore. Bookmark it: it can save you a wasted service call, or tell you when a problem genuinely needs a technician.
Before You Do Anything: The 5-Minute Reset
Many error codes are one-off glitches. Before booking a repair: switch the unit off at the remote, then turn off the power at the breaker or isolator for 5 minutes, and restart. If the code returns, use the tables below.
Daikin Error Codes
| Code | Meaning | DIY or Technician? |
|---|---|---|
| A3 | Drain water level abnormal — clogged drain pipe or failed drain pump | Technician (drainage clearing) |
| A5 | Anti-freeze protection — dirty coil or low refrigerant | Technician (wash or gas check) |
| E7 | Outdoor fan motor fault | Technician |
| U0 | Refrigerant shortage | Technician (leak check + top-up) |
| U4 | Indoor–outdoor communication error | Try reset; technician if repeats |
More on our Daikin servicing page.
Mitsubishi Electric (Starmex) Error Codes
| Code | Meaning | DIY or Technician? |
|---|---|---|
| P5 | Drain overflow protection — drainage likely choked | Technician |
| P8 | Abnormal pipe temperature — dirty filters/coil or gas issue | Clean filters first; technician if repeats |
| E6 | Indoor–outdoor communication fault | Try reset; technician if repeats |
| U8 | Outdoor fan abnormal | Technician |
| Blinking operation light | Self-diagnosis signal — count the blinks and note the pattern | WhatsApp us the pattern |
More on our Mitsubishi servicing page.
Panasonic Error Codes
| Code | Meaning | DIY or Technician? |
|---|---|---|
| H11 | Indoor–outdoor communication failure | Try reset; technician if repeats |
| H16 | Outdoor current transformer issue | Technician |
| F11 | 4-way valve switching abnormality | Technician |
| F90 | Power factor correction protection | Technician |
| F91 | Refrigeration cycle abnormal — usually low gas | Technician (leak test) |
More on our Panasonic servicing page.
Midea Error Codes
| Code | Meaning | DIY or Technician? |
|---|---|---|
| E1 | Indoor–outdoor communication error | Try reset; technician if repeats |
| E3 | Indoor fan speed abnormal | Technician |
| E5 | Outdoor unit protection — voltage or airflow | Check condenser not blocked; then technician |
| EC | Refrigerant leak detected | Technician (leak check + top-up) |
| P0 | IPM module protection — inverter fault | Technician |
More on our Midea servicing page.
LG Error Codes
| Code | Meaning | DIY or Technician? |
|---|---|---|
| CH01 / CH02 | Air / pipe temperature sensor fault | Technician (sensor swap) |
| CH05 | Indoor–outdoor communication fault | Try reset; technician if repeats |
| CH10 | Indoor fan motor fault | Technician |
| CH38 | Refrigerant shortage | Technician (leak check + top-up) |
More on our LG servicing page.
Three Rules That Save You Money
- Codes about drainage (A3, P5) — stop using the unit; continued running can flood your wall. This is usually a quick, inexpensive fix.
- Codes about refrigerant (U0, F91, EC, CH38) — insist on a leak check before any gas top-up. Gas does not run out on its own.
- Communication faults (U4, E6, H11, E1, CH05) — often cleared by a power reset. If it returns within days, wiring or a control board needs attention.
Frequently Asked Questions
Can I keep using the aircon when an error code shows?
For drainage codes, no — you risk water damage. For most other codes the unit protects itself by stopping. Do the 5-minute power reset once; if the code returns, book a diagnosis.
How much does it cost to fix an error code?
It depends on the cause: drainage clearing and sensor swaps are inexpensive, while PCB or compressor faults cost more. We diagnose on site and quote before any work begins.
Why does my error code keep coming back after reset?
A recurring code means a real hardware fault, not a glitch — most commonly dirty coils, a choked drain, a failing sensor or low refrigerant. Repeated resets only delay the fix.