Kelvinator split AC indoor unit displays E1 and stops cooling intermittently.

Safety first: Turn off the AC using the remote, switch off the wall isolator, and unplug the unit or turn off the circuit breaker before opening any covers.

Steps to check and fix:

• Power reset: Leave the power off for 5–10 minutes, then restore power and see if E1 clears. If it returns, continue.
• Access the indoor PCB: Remove the front fascia and filter of the Kelvinator indoor unit. Remove the small screw(s) and gently open the PCB cover.
• Locate the room sensor: Find the small thermistor (usually a bead-type sensor on thin wires) clipped near the indoor air intake grille and plugged into the indoor PCB.
• Check connections: Ensure the thermistor plug is fully seated on the PCB and that the wires are not cut, pinched, or corroded.
• Test the sensor: With a multimeter set to resistance (kΩ), measure across the thermistor leads (with power still OFF). At room temperature (around 25°C), most Kelvinator NTC sensors read roughly 5–20 kΩ. If it reads open (OL) or near 0 Ω, the sensor is faulty.
• Replace if faulty: If readings are abnormal, replace the room temperature sensor with a Kelvinator-compatible NTC thermistor assembly. Route the new sensor in the same position and clip it securely.
• Inspect PCB: If a known-good sensor still triggers E1, the indoor control PCB thermistor circuit may be defective and the PCB may need replacement.

When to call a technician: If you are not comfortable using a multimeter or accessing the PCB, or if the PCB appears burnt or damaged, contact an authorized Kelvinator service center.