Dehumidifier stops and displays E1 on the control panel; buttons may not respond or unit will not start a cycle.

Safety first: Unplug the Tosot dehumidifier before removing 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 5–10 minutes, then plug back in and try again. Sometimes E1 can be a temporary logic fault.
• Locate the ambient sensor: Remove the front or side grille (depending on model). The room temperature sensor is usually a small probe or bullet-style thermistor clipped near the air intake or evaporator coil, with two thin wires going to the main PCB.
• Inspect the wiring: Check for broken, pinched, or chewed wires, and ensure the sensor plug is fully seated on the control board. Reseat the connector several times to clear oxidation.
• Check sensor resistance: With a multimeter set to ohms, measure the sensor across its two leads (unit unplugged). At room temperature (~25°C / 77°F), most Tosot NTC sensors read between 5–20 kΩ. If it reads open (OL) or near 0 Ω, the sensor is defective.
• Replace if faulty: If resistance is out of range or the wiring is damaged, replace the ambient temperature sensor (NTC thermistor) with a Tosot-compatible part. Route the new sensor away from sharp metal and moving parts.
• Control board check: If a known-good sensor still gives E1, the main control board’s sensor input may be defective and the board will need replacement.

When to stop: If you are not comfortable using a multimeter or removing panels, contact a qualified appliance technician.