Unit stops cooling and displays E1, fan may still run.

Safety first: Disconnect the Sencor air conditioner from power before opening any panels.

• Step 1 – Reset: Unplug for 5–10 minutes and reconnect. If E1 reappears immediately, proceed.
• Step 2 – Locate room sensor: On Sencor portable and wall units, the room NTC sensor is usually clipped near the air intake grille or behind the front filter, connected by thin wires to the main PCB.
• Step 3 – Visual inspection: Check that the sensor probe is intact, not broken or pulled out of its clip. Ensure the wires are not cut, pinched, or melted.
• Step 4 – Check connections: Follow the sensor wires to the main PCB and reseat the small connector. Look for corrosion or loose pins.
• Step 5 – Resistance test (for advanced DIY): With the unit unplugged, disconnect the sensor and measure resistance with a multimeter. At around 25°C, most Sencor NTC sensors read ~5–10 kΩ (exact value depends on model). If reading is infinite (open) or near 0 Ω (short), replace the sensor.
• Step 6 – Replace sensor: Order the correct Sencor room temperature sensor by model number. Clip the new sensor in the same location and connect to the PCB.
• Step 7 – PCB check: If a known-good sensor still triggers E1, the main control PCB sensor circuit may be defective and should be replaced by a technician.