Daikin AC Error Code F3 — What It Means & How to Fix It

What Does This Error Mean?

F3 on a Daikin AC means the discharge pipe temperature sensor (also called the discharge thermistor) has detected a fault. This sensor monitors the temperature of the refrigerant leaving the compressor. Daikin shuts down the system to protect the compressor until the sensor issue is resolved.

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

Discharge pipe thermistor has failed or is reading out of range
Thermistor connector loose or disconnected at the outdoor PCB
Thermistor wiring damaged — chafed, cut, or corroded
Thermistor probe dislodged from the discharge pipe — no longer making proper contact
Outdoor PCB fault causing incorrect reading of the thermistor signal

How to Fix It

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

Allow the system to power down completely before doing anything.
Wait 5 minutes, then restore power and restart the AC.

If F3 was caused by a temporary sensor glitch, a power cycle may clear it. If F3 returns immediately, the sensor or its wiring has a real fault.
Check whether F3 appears immediately on startup or only after the system runs for a while.

Immediate F3 usually means an open circuit — broken wire or disconnected connector. F3 that appears after running suggests a sensor that fails when it heats up.
Do not continue restarting — if F3 persists, call a Daikin-authorised technician.

Running the compressor without a working discharge thermistor can cause overheating and expensive compressor damage.
Tell the technician exactly when F3 appears and how long the AC ran before the error.

This information helps the technician diagnose the fault faster and reduces your service visit time.

When to Call a Professional

F3 requires a licensed HVAC technician. The discharge pipe and compressor area involve refrigerant lines and high-voltage components. A technician will test thermistor resistance with a multimeter and replace the sensor if faulty — typically a low-cost repair.

Frequently Asked Questions

What is the discharge pipe thermistor in a Daikin AC?

The discharge thermistor is a temperature sensor clamped to the pipe that carries hot refrigerant gas out of the compressor. It monitors the compressor outlet temperature to ensure safe operation. If this temperature gets too high — or if the sensor fails — the F3 code triggers to prevent compressor damage.

Can I use my Daikin AC with an F3 error showing?

No — Daikin will not allow the compressor to run when F3 is active. The system locks out to protect the compressor from overheating damage. Arrange for a technician visit before trying to use the AC.

How much does it cost to fix a Daikin F3 error?

A discharge thermistor sensor part typically costs Rs 300–800 in India or $15–40 internationally. With technician labour, expect a total repair cost of Rs 1,500–3,500 in India or $100–200 internationally. Always request a quote before approving work.