Display shows E1 and the Klarstein coffee maker will not start a brew cycle.

Safety first: Unplug the coffee maker before inspecting internal parts. Allow the machine to cool completely.

Step-by-step checks:

• Reseat the water tank: Remove the water tank completely, check that the bottom valve opens freely when pressed, then reinstall it firmly until it clicks into place. Many Klarstein models (e.g. Aromatica, BellaVita, Arabica) will show E1 if the tank is not fully engaged.
• Check water level: Fill the tank at least to the MIN mark. Some Klarstein units trigger E1 when the float sensor detects an empty tank.
• Free the float: Look inside the tank for a small plastic float. If it is stuck due to scale or debris, rinse the tank with warm water and a little dish soap, then move the float up and down until it moves freely. Rinse thoroughly.
• Clean the tank contacts: On models with external tank contacts, wipe the metal contacts on the tank and on the machine body with a soft cloth slightly dampened with white vinegar, then dry completely.
• Inspect wiring (advanced): With the unit unplugged, remove the rear or bottom cover (if accessible) and check the harness from the tank sensor/reed switch to the main control board for loose plugs or damaged wires. Reseat any loose connectors.

If E1 persists after these steps, the level sensor or reed switch assembly is likely defective and should be replaced.