Display shows E03 and the coffee maker does not heat water or brew; sometimes accompanied by a clicking sound.

Safety: Unplug the coffee maker and let it cool for at least 30 minutes. Do not open the housing unless you are qualified; internal components can retain heat and voltage.

This error indicates the control board is receiving abnormal temperature readings.

• Allow full cool‑down: If the unit was used repeatedly, let it cool completely, then plug back in and try again. Overheat protection can temporarily trigger E03.
• Descale the heater: Heavy scale on the Braun thermal block can cause hot spots and sensor errors. Run a full descaling cycle using Braun‑approved descaler or a 1:1 vinegar solution, then flush with 2–3 tanks of fresh water.
• Check ventilation: Ensure the coffee maker is not pushed tightly against a wall or under a low cabinet that traps heat.
• Power reset: Unplug for 10 minutes to reset the control board, then test.

If E03 reappears, the NTC sensor or control board likely needs replacement. This requires disassembly of the base and heater assembly and should be done by a service technician.