Air Conditioner
Walton
Updated Jul 24, 2026
Walton AC F3 Error — Compressor Discharge Sensor Fault & Fix
F3
Walton · Air ConditionerF3 on a Walton AC means the compressor discharge temperature sensor (T5 thermistor) on the…
Quick answer
F3 on a Walton AC means the compressor discharge temperature sensor (T5 thermistor) on the outdoor unit has an open or short circuit.
What F3 means
The discharge sensor monitors the hot gas leaving the compressor. If it fails, the board cannot protect the compressor from overheating, so it stops with F3. This is different from the compressor actually overheating — F3 means the sensor itself is broken.
How to fix it
- Power off and wait for the compressor to cool (at least 15 minutes).
- Locate the sensor — clamped to the compressor discharge pipe (the hottest pipe on the outdoor unit).
- Check for heat damage — the wire insulation may have melted.
- Reseat the connector at the outdoor PCB.
- Measure resistance — replace if faulty.
- Use heat-resistant cable ties when routing the new sensor wire near the compressor.
What does the F3 code mean?
F3 indicates the compressor discharge temperature sensor (T5) has an open or short circuit on the outdoor unit.
Common causes
- Failed discharge thermistor
- Heat damage to sensor wire from compressor proximity
- Loose connector on the outdoor PCB
- Outdoor PCB fault (rare)
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How to fix the F3 error
Power off and wait 15 minutes
Let the compressor cool.
Locate the sensor
Clamped to the discharge pipe.
Check for heat damage
Inspect wire insulation.
Reseat connector
At the outdoor PCB.
Measure resistance
Replace if open or zero.
Use heat-resistant ties
When routing the new sensor wire.
Safety first: The discharge pipe can exceed 100 degrees C. Wait for complete cooling before handling.
Part you may need: Compressor discharge temperature sensor (NTC thermistor)
This sensor fails more often than others due to its proximity to extreme heat. Walton service centres stock them.
Frequently asked questions
Is F3 dangerous?
Not directly — F3 stops the compressor, which is the safe response. But fix it promptly to restore cooling.
Can I run without the discharge sensor?
No — the board will not start the compressor without valid discharge temperature feedback.
✎ Written by
REZAUL Karim (Riad)
REZAUL Karim (Riad) is the founder of ErrFixHub and a hands-on electronics and home-appliance repair specialist with over 15 years of experience diagnosing and fixing air conditioners, washing machines, refrigerators, inverters and other household appliances. He built ErrFixHub to turn cryptic error codes into clear, step-by-step fixes anyone can follow — cross-checking every code against manufacturer documentation and real repair-bench experience.
