Daikin AC Error Code F1 — What It Means & How to Fix It

What Does This Error Mean?

F1 on a Daikin AC means the indoor coil (evaporator pipe) temperature thermistor has a fault. This sensor monitors the temperature of the indoor heat exchanger coil to protect against freezing and control cooling efficiently. Daikin stops cooling when F1 appears to prevent the indoor coil from freezing solid.

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

Indoor coil thermistor has failed — resistance value outside the normal range
Thermistor connector loose or disconnected at the indoor PCB
Thermistor wire damaged — pinched by the indoor unit panel or corroded
Thermistor probe dislodged from the evaporator coil pipe
Indoor PCB fault causing incorrect interpretation of the thermistor signal

How to Fix It

Turn off the AC at the remote and at the circuit breaker.

Wait 5 minutes before restarting. If F1 was a transient error, it may clear after a reset.
Check whether F1 appears immediately on startup or only after the AC runs for a while.

Immediate F1 = broken wire or disconnected connector. F1 after running = thermistor that drifts out of range when cooled.
Check that the indoor unit air filter is clean.

A heavily blocked filter restricts airflow over the evaporator coil, causing it to cool abnormally and potentially triggering sensor errors.
If F1 persists, call a Daikin technician — the indoor coil thermistor needs testing and likely replacement.

This is a low-cost repair when the thermistor alone has failed — typically Rs 300–600 for the sensor plus visit charge.

When to Call a Professional

F1 requires a licensed HVAC technician. The indoor unit's evaporator area involves refrigerant pipes and electrical components. Daikin India customer care: 1800-103-3666. A technician will test thermistor resistance and replace the sensor if faulty.

Frequently Asked Questions

Can a dirty filter cause Daikin F1?

Indirectly — a severely blocked filter starves the evaporator coil of airflow, causing it to over-cool. This pushes the coil temperature sensor reading to the edge of its range, which can trigger F1 on a thermistor that is already slightly degraded. Always clean the filter monthly and check whether F1 clears before calling for service.

How much does Daikin F1 repair cost in India?

An indoor coil thermistor typically costs Rs 300–600 for the part. With the Daikin service visit charge and labour, total repair is usually Rs 1,200–2,500. Under warranty (1 year comprehensive, 5 years compressor), the repair is free.