Dehumidifier displays E3 and shuts down shortly after starting

Safety: Unplug the unit before opening the housing. Do not spray cleaners directly into the air intake.

• Locate the humidity sensor: On Stadler Form dehumidifiers, the RH sensor is typically mounted behind the front grille or in the air intake channel, often on a small daughter board or as a plastic-encased module.
• Visual inspection: Check for heavy dust, lint, or signs of liquid exposure on the sensor. If the sensor is coated, gently clean around it with a soft brush and compressed air. Avoid touching the sensing element directly.
• Check connections: Ensure the sensor plug is fully seated on the control board or sensor PCB. Look for corrosion or bent pins.
• Functional test: If you have access to another compatible Stadler Form unit or replacement sensor, swap the sensor to confirm the fault. If E3 clears with a new sensor, the original is defective.
• Replace sensor: Install the correct Stadler Form humidity sensor module for your model. Mount it in the same orientation so it is exposed to airflow but not directly in the water path.
• Control board: If a new sensor does not resolve E3, the main PCB may be faulty. Board-level repair is not recommended for DIY; replace the control board or contact a service center.