Dishwasher fills but does not heat the water; cycle may run long and end with E3.

Safety first: Isolate the dishwasher from the mains. Heating components operate at full mains voltage.

• Confirm symptom: Run a hot program and open the door carefully mid-cycle (after at least 20–30 minutes). If the water is cold and E3 appears, a heating fault is likely.
• Check wiring (visual): Remove the lower kick panel and side panels (if accessible). Inspect the wiring to the Baumatic flow-through heater and NTC sensor for burns, loose connectors, or damage.
• Check for limescale: Heavy limescale in hard water areas can overheat and damage the heater. If visible, descaling may help but usually the heater must be replaced.
• Component testing: Using a multimeter (only if you are competent), test the heater for continuity and the NTC for resistance change with temperature. Replace any open-circuit heater or out-of-range sensor.
• If unsure: Because this involves live mains and sealed components, most users should contact a professional to replace the heater or control board.