Beurer humidifier will not run and displays E1 shortly after power-on.

Safety first: Unplug the humidifier from the mains before opening any covers. Never work on the unit while it is connected to power.

Step-by-step checks:

• Power-cycle the unit: Unplug for 5 minutes, then plug back in and test. Temporary logic glitches can trigger E1.
• Inspect the air intake area: On many Beurer humidifiers (e.g. LB series), the temperature sensor (NTC) is located near the air intake grill. Check that the intake is not blocked by dust or fabric, which can cause abnormal readings.
• Access the sensor: Remove the water tank and base cover (usually Phillips screws on the underside). Locate the small bead or capsule-type sensor on two thin wires leading to the main PCB.
• Check connections: Ensure the sensor plug is firmly seated on the control board. Look for broken or pinched wires, especially where the harness passes through plastic guides.
• Test the sensor (for advanced users): With the unit unplugged, disconnect the sensor and measure resistance with a multimeter. A typical NTC will read between 5–100 kΩ at room temperature. An open circuit (OL) or 0 Ω indicates a failed sensor.
• Clean light corrosion: If the connector pins are slightly oxidized, clean gently with contact cleaner and a cotton swab, then reconnect.
• Replace if faulty: If the sensor is open/shorted or the insulation is damaged, replace it with a compatible Beurer NTC temperature sensor assembly for your exact model.

When to stop: If E1 persists after sensor replacement or you are not comfortable using a multimeter, contact an authorized Beurer service center.