Adler ice maker shows E04 and stops; water remains in the reservoir and no harvest occurs.

Safety first: Disconnect power and close the water supply valve.

• Access reservoir: Remove the front panel and top cover to reach the Adler water reservoir and float assembly.
• Inspect float movement: Manually move the float up and down. It should move freely without sticking. Clean any scale or slime with warm water and a mild ice-machine cleaner.
• Check sensor or switch: If your Adler model uses an electronic level sensor, inspect the probe surfaces and clean them thoroughly. For mechanical switches, test continuity with a multimeter while moving the float.
• Secure wiring: Ensure the harness from the level sensor to the control board is firmly connected and not pinched.
• Replace faulty parts: If the float is waterlogged or the switch fails continuity tests, install a new Adler water level switch or sensor assembly.
• Flush and test: Refill the reservoir, restore power, and run a test cycle to confirm the E04 code is cleared.