Air Conditioner
Walton
Updated Jul 26, 2026
Walton AC E5 Error — Indoor Coil Temperature Sensor Fault & Fix
E5
Walton · Air ConditionerE5 on a Walton AC means the indoor coil (evaporator pipe) temperature sensor has an open o…
Quick answer
E5 on a Walton AC means the indoor coil (evaporator pipe) temperature sensor has an open or short circuit.
What E5 means
The coil sensor is a thermistor clipped to the evaporator copper pipe. It monitors coil temperature for freeze protection and defrost control. Without it, the compressor could freeze the coil solid.
How to fix it
- Power off at the breaker.
- Open the indoor unit and find the coil sensor — a small probe clipped to a copper U-bend on the evaporator.
- Reseat the connector at the PCB.
- Measure resistance — at 25°C, typically about 5-10 kOhm (check your model's service manual). Replace if open or zero.
- Ensure good thermal contact — the probe must be firmly clipped to the pipe.
What does the E5 code mean?
E5 indicates the indoor evaporator coil pipe temperature sensor has an open or short circuit.
Common causes
- Faulty coil thermistor
- Loose connector on the indoor PCB
- Sensor displaced from the pipe
- Wiring damage
Advertisement · In-content
How to fix the E5 error
Power off
Isolate at the breaker.
Find the coil sensor
Clipped to a copper pipe on the evaporator.
Reseat connector
Check at the indoor PCB.
Measure resistance
Replace if open or zero.
Ensure pipe contact
Sensor must be firmly clipped for accurate reading.
Safety first: Evaporator fins are sharp — wear gloves when working inside the indoor unit.
Part you may need: Indoor coil pipe temperature sensor (NTC thermistor)
If the coil is frosted over when E5 appears, let it defrost completely before working on the sensor.
Frequently asked questions
What is the difference between E4 and E5?
E4 is the room air sensor; E5 is the coil pipe sensor. Different locations, but the diagnostic process is similar.
Can a frozen coil cause E5?
A frozen coil does not cause E5, but a failed E5 sensor can allow the coil to freeze.
✎ 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.
