Washer does not heat water; cycles take unusually long and E05 appears

Safety first: Unplug the washer and ensure the drum is cool before working near the heater.

Steps to check and address E05:

• Access the heater terminals: On many Siemens models, the heater is accessible from the rear. Remove the rear panel to expose the heater flange at the bottom of the tub.
• Inspect wiring: Check for burnt connectors or loose wires at the heater and NTC sensor.
• Test the heating element: With a multimeter, measure resistance across the heater terminals. Typical values are 20–30 Ω (check Siemens specs). If open circuit or shorted to ground, replace the heater.
• Test the NTC sensor: Measure resistance of the NTC at room temperature (often 4–20 kΩ). If reading is far off spec or does not change when warmed, replace the NTC sensor.
• Reassemble and test: Refit all connectors securely, reinstall the rear panel, and run a 60 °C cycle to confirm heating.

When to call a technician: If heater and NTC are good, the control module heater relay or triac may be faulty and should be serviced by a professional.