E6
Daikin Split AC
Severity: ModerateWhat Does This Error Mean?
E6 on a Daikin AC means the outdoor coil thermistor — the sensor that monitors the temperature of the condenser coil — has a fault. This sensor helps the inverter board regulate compressor speed efficiently. When it fails or reads an impossible value, the AC shuts down to prevent running blind without coil temperature data.
Affected Models
- Daikin FTKF Series
- Daikin FTKG Series
- Daikin ATKF Series
- Daikin Inverter Split AC (all models)
- Daikin 1 Ton / 1.5 Ton / 2 Ton Inverter
Common Causes
- Outdoor coil thermistor has failed — resistance value out of specification
- Thermistor probe dislodged from the coil pipe
- Connector at the outdoor PCB loose or corroded
- Thermistor wiring damaged by weather or rodent activity
- Outdoor PCB fault causing incorrect sensor reading
How to Fix It
-
Turn off the AC and switch off the circuit breaker.
Wait 5 minutes, restore power, and restart once.
-
If E6 clears after a power cycle, monitor the unit for the next hour.
A transient E6 may not return. If E6 comes back after the system has been running for a while, the thermistor fails when it heats up — a classic sign of a degraded sensor.
-
If E6 persists, call a Daikin authorised technician.
The thermistor itself is a low-cost part — the majority of the repair cost will be the technician's visit fee.
When to Call a Professional
E6 requires an authorised Daikin technician. The outdoor coil and associated wiring are inside the outdoor unit which contains high-voltage components.
Frequently Asked Questions
What does the outdoor coil thermistor do in a Daikin inverter?
In a Daikin inverter AC, the outdoor coil thermistor provides real-time temperature data to the inverter board. This data is used to adjust compressor speed for maximum efficiency. A failed sensor causes the inverter to operate without this input, triggering a safety shutdown.
Is E6 the same issue as E5 on a Daikin?
No — E5 is an outdoor fan motor fault (the motor that drives the fan is not working), while E6 is an outdoor coil temperature sensor fault (a sensor has failed). Both are outdoor unit issues but require different repairs.