Machine powers on but does not heat; brewing does not start and E02 appears on the display.

Safety first: Unplug the coffee maker and allow at least 30 minutes for internal components to cool before opening any covers.

• Power reset: Disconnect the machine from mains for 5 minutes, then reconnect and test. Transient sensor errors can sometimes clear with a reset.
• Check for obvious overheating signs: Smell for burnt odor around the top or rear vents. If you notice melting or scorching, do not use the machine until inspected by a technician.
• Clean ventilation: Ensure the ventilation slots are not blocked by cabinets or objects. Overheating can trigger E02.
• Descale the machine: A heavily scaled thermoblock can overheat. Run a full descaling cycle using a Grundig-approved descaler according to the user manual, then rinse with 2–3 full tanks of fresh water.
• Professional check: If E02 returns immediately after reset and descaling, the NTC sensor, thermofuse, or thermoblock assembly likely needs replacement. This involves live mains and pressurized hot water; contact a qualified service technician.