The “Blind” AC Problem
The CH 01 Error refers to the Indoor Air Sensor (the small black probe usually located in front of the air filters). Its job is to constantly measure the room temperature.
“Open” or “Short”: This means the electrical circuit is broken. The most common reason in India is that a rat has chewed through the thin wires, or the sensor itself has failed due to moisture/age.
1 DIY Visual Checks
Rat Damage Inspection
Open the front grill. Look at the right side where the wires go into the PCB box. Are the thin black wires chewed? This accounts for 90% of CH 01 errors.
Loose Connector
If the AC was just serviced or moved, the sensor plug (jack) on the PCB might have come loose. A gentle push might fix it.
Moisture Damage
If water is dripping inside the unit, it can soak the sensor head, causing erratic resistance readings (Short Circuit).
Atlas Aircon Repair Protocol
How we fix the CH 01 Fault:
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01.
Resistance Check (Ohms) We unplug the sensor and use a multimeter. A healthy LG sensor must read **10k Ohms** at 25°C. Any other value confirms a bad sensor.
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02.
Wire Repair vs Replace If rats cut the wire in the middle, we can rejoin and solder it. If the cut is too close to the sensor head or jack, we replace the whole unit.
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03.
PCB Jack Inspection We check the PCB connector for rust or carbon. Sometimes the sensor is fine, but the PCB port is dirty.
Estimated Repair Cost (Atlas Aircon)