Diagnosis
Error code E1 indicates an ambient temperature sensor fault. The control board cannot read the room temperature, causing a safety shutdown.
How to Fix It
Unplug the unit for 5 minutes to perform a hard reset. Plug it back in. If E1 clears, it was a temporary glitch. If E1 returns immediately, the sensor or its wiring is faulty.
If That Didn't Work
The sensor is typically located on the evaporator coil or near the air intake. Access requires removing the outer casing. Visually inspect the small two-wire sensor for damage or a disconnected plug. Do not attempt this unless you are comfortable with basic disassembly.
Heads Up
An E1 error will prevent all operation. This is not a user-serviceable error if a reset fails. It requires qualified technician intervention for sensor testing or control board replacement.