Philips dehumidifier stops and displays E1 on the control panel; unit may beep and refuse to start dehumidifying.

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

Step-by-step checks:

• Power reset: Unplug the unit for 5–10 minutes, then plug back in and try again. Sometimes E1 is a temporary sensor read error.
• Inspect the ambient sensor: Locate the room temperature sensor (usually a small NTC probe near the air intake grille or evaporator coil, connected by two thin wires to the main PCB). Check for broken insulation, pinched wires, or signs of corrosion.
• Check connectors: Gently unplug and re-seat the sensor connector on the main control board. Look for bent pins or oxidation. Clean lightly with contact cleaner if available and fully dry before reconnecting.
• Measure resistance (advanced): With the unit unplugged, disconnect the sensor and measure its resistance with a multimeter. Compare to a typical NTC curve (e.g., ~10kΩ at 25°C). If it reads open (infinite) or near 0Ω, the sensor is defective.
• Board inspection: Inspect the main PCB for burnt components or cracked solder joints around the sensor input. If damage is visible, the board may need replacement.

When to stop: If the sensor and wiring look intact but E1 persists, replacement of the main control PCB should be done by a qualified technician due to mains voltage and refrigerant system proximity.