Display shows E5 and the Klarstein coffee maker does not pump water through the system.

Safety first: Unplug the machine before opening any covers. Hot water and steam can cause burns.

Basic user checks:

• Prime the pump: Fill the water tank completely, reinstall it, then start a hot water or rinse cycle (if available). Sometimes running several short cycles clears air from the pump.
• Descale: Heavy scale can block the flow meter or pump. Run a full descaling cycle according to the Klarstein manual.

Internal checks (advanced):

• Remove the side or rear panel to access the vibration pump and flow meter (usually a small plastic disc with two hoses and wires).
• Check hoses for kinks or blockages and ensure hose clamps are tight.
• Listen for the pump when a brew cycle is started. A silent pump may indicate a failed coil or no power from the board.
• Inspect the flow meter wiring to the control board; reseat the connector.

If the pump hums but no water moves, the pump may be seized or the flow meter blocked. Replace the faulty component with a Klarstein-compatible vibration pump or flow meter.