Aircon Diagnostics

Use the right tool first to narrow likely fault patterns before approving repair scope.

Choose your tool

Use symptom-based, code-based, or blink-pattern guidance depending on what you can observe right now.

Which one should I use?

Start with the clearest signal you already have.

No code shown, just behavior change

Use Symptom Checker first.

Controller shows a fault code (e.g. U4, CH21, E6)

Use Error Code Lookup.

Light is blinking but no explicit code

Use Blinking Light Lookup.

After diagnosis, read the relevant guides

Move from tool output into deeper explainers and real diagnosis scenarios.

Browse symptom guides Browse parts explainers Browse case studies Browse all articles

Popular brand shortcuts

Daikin error codes Mitsubishi error codes Panasonic blinking lights LG blinking lights

Major vs targeted repair

Not cooling traced to capacitor fault, not compressor failure

Aircon case in Jurong West, Singapore: electrical/control traced to failed run capacitor — compressor motor intact after targeted diagnosis checks.

Recurring gas loss

Cooling loss traced to refrigerant leak, not just low gas

Aircon case in Tampines, Singapore: cooling loss traced to slow refrigerant leak at pipe connection after targeted diagnosis checks.

Post-service failure

Not cold after servicing traced to partially closed valve

Aircon case in Bedok, Singapore: post-service issue traced to service valve left partially closed after routine service after targeted diagnosis checks.

Not sure which tool fits your situation?

Send us what you see right now and we'll tell you the next best diagnostic step.

Describe it on WhatsApp