Dishwasher stops mid-cycle, water is not heating and E04 appears on the display.

Safety: Disconnect mains power and allow the machine to cool completely before testing heating components.

• Check for obvious overheating: Inspect the underside of the tank where the heating element and thermostats are mounted. Look for signs of burning or melted wiring.
• Test heating element: Disconnect the element terminals and measure resistance with a multimeter. Compare to Wexiodisk specifications (typically a few ohms). An open circuit indicates a failed element that must be replaced.
• Inspect high-limit thermostat: Locate the manual-reset safety thermostat on the tank. If it has a reset button, press it firmly until it clicks. If it trips repeatedly, investigate for low water level or limescale on the element.
• Check temperature sensor (NTC): Measure resistance at room temperature and compare to the service manual curve. Replace if reading is out of range or unstable.
• Control board check: If all components test good but no voltage is supplied to the heater during wash, the heater relay or triac on the PCB may be defective and requires professional repair or board replacement.

Because heating circuits involve high current, replacement of elements or control boards should be done by a qualified technician.