Klarstein air conditioner stops cooling and displays E2 on the control panel.

Safety warning: Disconnect the unit from power before removing covers. Sharp metal edges around coils can cause injury; wear gloves.

Diagnostic and repair steps:

• Access the evaporator: Remove the front or side cover (depending on model) to expose the indoor evaporator coil.
• Locate the sensor: The evaporator NTC sensor is usually clipped or inserted into the evaporator fins near the center or outlet side, with two wires leading back to the PCB.
• Check mounting: Ensure the sensor bulb is firmly attached to or inserted into the fins. If it has fallen out, reinsert and secure it with the original clip or aluminum tape.
• Inspect wiring: Look for broken insulation, pulled wires, or loose connectors. Reseat the connector on the main PCB.
• Test resistance: With the sensor unplugged and the unit powered off, measure resistance. Compare to room temperature NTC values; if reading is open or shorted, replace the sensor.
• Replace sensor: Install a new Klarstein evaporator NTC sensor assembly, routing wires away from the fan and sharp edges.
• PCB check: If a new sensor does not clear E2, the main control PCB sensor circuit is likely defective and must be replaced.