Machine does not start brewing; display shows E01 shortly after pressing the start button.

Safety first: Unplug the Grundig coffee maker from the mains before inspecting parts. Never work on the unit while it is connected to power.

• Check water tank seating: Remove the water tank completely and reinsert it firmly until it clicks into place. Many Grundig models use a small tab and microswitch to detect the tank.
• Verify water level: Fill the tank at least to the minimum mark. Some models will trigger E01 if the float is below the sensor even if a small amount of water is present.
• Inspect the float: Look inside the tank for a plastic float. Make sure it moves freely up and down. If it is stuck due to scale, clean the tank with warm water and a mild descaler, then rinse thoroughly.
• Check tank sensor area: On the machine body where the tank sits, inspect for debris or scale buildup around the sensor window or microswitch lever. Wipe gently with a damp cloth and dry.
• Test again: Reassemble, plug in, and try a brew cycle. If E01 persists, the tank detection switch or level sensor may be faulty and require replacement.