Unit stops cooling or heating and displays E2, compressor may not start.

Safety first: Unplug the unit. Sharp metal edges around the evaporator coil can cause injury; wear cut-resistant gloves.

• Step 1 – Access evaporator: Remove the front cover and air filters. On portable Sencor units, remove the upper housing screws to expose the evaporator coil.
• Step 2 – Locate sensor: Find the small probe clipped or taped to the evaporator fins with two thin wires leading to the PCB.
• Step 3 – Check placement: Ensure the sensor is firmly attached to the coil surface. If it has fallen off, reattach using aluminum tape or the original clip.
• Step 4 – Inspect wiring: Look for cuts, pinches, or corrosion on the sensor wires and connector. Reseat the connector on the main PCB.
• Step 5 – Test sensor (advanced): With the sensor disconnected and the unit unplugged, measure resistance. Compare to the room sensor value at similar temperature. A reading of 0 Ω or infinite indicates a bad sensor.
• Step 6 – Replace sensor: Install a new Sencor evaporator NTC sensor, routing the wires away from the fan and sharp edges.
• Step 7 – PCB evaluation: If E2 persists with a new sensor, the main PCB may be faulty and should be replaced by a professional.