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

What Does This Error Mean?

F3 on a Panasonic AC means the outdoor heat exchanger thermistor has a fault. This thermistor monitors the temperature of the outdoor coil during operation to protect the compressor. When the sensor fails or reads an impossible value, Panasonic triggers F3 and stops the compressor.

Affected Models

Panasonic Inverter Split AC (all capacities)
Panasonic CS-SU series
Panasonic CS-YU series
Panasonic CS-XU series
Panasonic NanoeX series

Common Causes

Outdoor heat exchanger thermistor failed — open or short circuit in the sensor
Thermistor wiring damaged by UV exposure, rodent activity, or physical impact
Connector at the outdoor PCB loose or corroded from moisture
Thermistor probe not clipped securely to the heat exchanger pipe
Outdoor control PCB fault producing incorrect sensor signal

How to Fix It

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

Wait 5 minutes before powering back on.
Restore power and start the AC. Observe whether F3 reappears immediately or after the unit runs for a while.

F3 on immediate startup = open circuit (broken wire or disconnected connector). F3 after running = thermistor that fails when heated.
Check the outdoor unit for obvious external damage, blockages, or signs of pest activity.

Rodents can chew sensor wiring inside the outdoor unit. If you see pest evidence, mention it to the technician.
Book a service visit via Panasonic care (1800-103-1333 or panasonic.com/in/support).

Have your model number and purchase date ready when calling.

When to Call a Professional

F3 requires a Panasonic authorised service technician. Panasonic India customer care: 1800-103-1333. The technician will measure thermistor resistance at ambient temperature and compare to the specification chart in the service manual.

Frequently Asked Questions

Is F3 on a Panasonic inverter AC different from F3 on a non-inverter?

On Panasonic inverter models, F3 consistently refers to the outdoor heat exchanger thermistor. On older non-inverter models the fault codes may differ — check the user manual for your specific model. If in doubt, contact Panasonic support with your model number for confirmation.

How much does a Panasonic AC thermistor cost in India?

An outdoor heat exchanger thermistor for Panasonic typically costs Rs 300–700. Total service cost including labour and the service visit is usually Rs 1,200–2,800. Under warranty, parts and labour are covered — verify warranty status before agreeing to paid repair.