Unit will not run; display shows E1 shortly after power-on.

Safety first: Unplug the NewAir air conditioner from the wall outlet before opening any panels. Do not work on the unit while it is connected to power.

Steps to check and correct:

• Power reset: Unplug the unit for 5 minutes, then plug back in and try again. Sometimes E1 can be a transient sensor reading error.
• Locate the room sensor: On most NewAir portable and window units, the room temperature sensor (NTC thermistor) is clipped near the front air intake grille or mounted on the evaporator coil bracket. Remove the front filter and front cover as needed.
• Inspect wiring: Look for broken, pinched, or corroded wires between the sensor and the main control PCB. Reseat the sensor connector on the control board.
• Test the thermistor: With a multimeter set to resistance (ohms), measure the sensor at room temperature (around 77°F / 25°C). Typical NTC sensors read between 5k–20kΩ at room temperature. An infinite reading indicates an open sensor; near 0Ω indicates a shorted sensor.
• Replace if faulty: If readings are out of range or the sensor is physically damaged, replace it with a compatible NewAir room temperature sensor (NTC thermistor). Route the new sensor wiring away from sharp metal edges and secure with zip ties.
• Check control board: If a known-good sensor still triggers E1, the sensor input on the main control PCB may be defective and the board will need replacement.