Daikin aircon C3 error code
Use this Daikin C3 error code guide to decide when to stop resetting, what to capture, and what to check before parts are quoted.
What does Daikin C3 mean?
Daikin C3 is listed as malfunction of drain level sensor in Ceiling Cassette, Ceiling Suspended, Inverter Split rows such as SM-TS3 matrix overview. The loaded row is source-backed by official diagnostic material. Confirm the exact model, series, or signal row before accepting a parts quote.
Open, shorted, displaced, or out-of-range thermistor or pressure-sensor reading.
Loose sensor connector, damaged sensor harness, or water-affected wiring.
PCB input fault after the sensor and wiring readings are confirmed.
What to do now
Use these steps before another reset, sensor check, or PCB quote.
Treat it as a fault signal
If C3 returns or cooling is still abnormal, stop treating it as a simple reset issue.
Reset C3 once
Capture the C3 display first, then power-cycle once only and note whether the same fault returns.
Send these to us
C3 error code, a clear display photo, Daikin model stickers, affected rooms, reset result, and when the fault appears
Source-specific guidance
These diagnostic-reference notes help match the code to the exact model. Electrical, refrigerant, wiring, resistance, and component checks are technician work, not DIY steps.
| Source detail | What it says |
|---|---|
| Source repair action | Stop the system if it smells burnt, leaks, or trips power; note the exact model and code before booking diagnosis. |
| Singapore / model note | Official Daikin SM-TS3 page-1 matrix row. The matrix gives the broad malfunction wording, but not the detailed cause table; confirm the exact model and installed accessories before treating it as final. |
What to check before repair
Use this split to separate safe evidence capture from the tests a technician should prove before quoting parts.
| You can check | Technician should confirm |
|---|---|
| Before resetting C3, take a clear display photo. | Confirm which sensor C3 maps to on the exact model table. |
| Capture the Daikin indoor and outdoor model stickers so the correct family row is used. | Measure the sensor value against the service-manual resistance or voltage range. |
| Note whether one room, several rooms, or the whole system is affected, plus whether it returns after one reset. | Check connector condition, harness continuity, and PCB input before replacing boards. |
What changes the next step
These clues decide whether the first check is room-side, shared outdoor-side, refrigerant-side, source-table, or model-family confirmation.
| What you see | What it points to |
|---|---|
| Only one indoor unit shows C3. | The affected room, indoor board path, wiring route, or local component should be checked first. |
| Several rooms or the outdoor unit show the same C3 fault. | The shared outdoor side, power path, communication trunk, or refrigerant circuit needs priority checking. |
| The fault appears immediately even before the unit cools properly. | Sensor value, connector, harness, and PCB input should be tested in that order. |
| The model family is different from the row you found online. | Use the model or series filter first; same-looking codes can still belong to different diagnostic tables. |
| The model belongs to Ceiling Cassette, Ceiling Suspended, Inverter Split rows such as SM-TS3 matrix overview. | The loaded row is source-backed by official diagnostic material. Use the matching source row before quoting parts. |
Sensor or PCB decision
Daikin C3 is usually repair-first if a sensor or harness reading is confirmed. Board replacement should wait until the sensor circuit is tested.
Sensor replacement is usually targeted when resistance or voltage readings are out of range.
Harness or connector damage can look like a sensor fault until continuity is checked.
PCB replacement is a later step if the sensor and wiring test correctly.
Daikin C3 questions
What does the Daikin C3 error mean?
Can I fix a Daikin C3 error myself?
Is it safe to keep running the aircon with a C3 error?
What causes a Daikin C3 error?
Will a Daikin C3 error need a repair or a full replacement?
What should I send a technician about a Daikin C3 error?
Confirm the fault
Share the error code, model number and symptoms so we can assess the likely cause.
Not the right code?
Browse the full Daikin list or check a few codes in the same fault category.
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Read next
Use these if the quote mentions the parts, checks, or repair path this code points to.