Dehumidifier stops and displays E1 shortly after power‑on; fan may run briefly then shut down.

Safety first: Unplug the dehumidifier before removing any covers. Capacitors on the control board can hold a charge; avoid touching bare terminals.

Steps to check and correct:

• Power reset: Unplug the unit for 5 minutes, then plug back in and try again. If E1 returns immediately, continue below.
• Access the control area: Remove the front or top cover (varies by model MJ‑/MJE‑/MJ‑E series). Keep screws organized.
• Locate the room thermistor: On Mitsubishi Electric dehumidifiers it is usually clipped near the air intake grille or on the evaporator inlet, connected by 2 thin wires to the main PCB.
• Inspect wiring: Check for broken, pinched, or corroded wires and loose connectors between the thermistor and the main PCB. Reseat the connector firmly.
• Measure resistance: With a multimeter set to kΩ, measure the thermistor at room temperature (~20–25°C). Typical NTC values are 5–20 kΩ at 25°C (refer to service data if available). If it reads open (OL) or near 0 Ω, the sensor is defective.
• Check at the PCB: If the sensor tests good at its plug, measure at the PCB side to confirm the harness is intact.
• Replace faulty parts: If the thermistor is out of spec, replace the room temperature sensor (NTC thermistor). If the sensor and harness are good but E1 persists, the main control PCB input is likely faulty and should be replaced.

When to call a technician: If you are not comfortable using a multimeter or accessing the PCB, or if the PCB needs replacement, contact an authorized Mitsubishi Electric service center.