Dishwasher fills but does not heat; cycle runs unusually long and dishes are cold at the end, with E3 displayed.

Safety first: Disconnect mains power and close the water supply. Heating components operate at full mains voltage.

• Confirm symptom: Run a short hot program and open the door mid-cycle (after 15–20 minutes). If the water and interior are cold and E3 appears, the heater circuit is suspect.
• Check wiring connections: Remove the lower front kick panel and side panel (if accessible). Inspect the wiring harness to the flow-through heater and NTC sensor for burns, loose connectors, or damage.
• Test heater resistance: With the dishwasher unplugged, disconnect the heater terminals and measure resistance with a multimeter. An open circuit or very high resistance indicates a failed heater.
• Inspect NTC sensor: Locate the NTC (temperature sensor) in the sump or on the heater body. Check its connector for corrosion. If available, compare its resistance at room temperature with service specifications.
• If heater or NTC is faulty: Replace the defective component. If both test correctly, the issue may be a heater relay or triac on the main control board, which usually requires board replacement or professional repair.