E13 error; ice maker heater does not operate, cubes stick in mold and do not eject.

Safety: Disconnect power before testing heater circuits.

• Check for stuck ice: Remove the ice bin and inspect the mold. If cubes are frozen solid to the mold and not releasing, the heater may not be working.
• Test heater resistance: Access the ice maker wiring and locate the heater leads (refer to Bosch wiring diagram). Disconnect and measure resistance; an open circuit indicates a failed heater.
• Inspect thermal fuse: Some Bosch ice makers include a small thermal cutoff in series with the heater. Test for continuity; replace if open.
• Replace ice maker assembly: Because the heater is often embedded, the practical repair is to replace the entire Bosch ice maker unit.
• Control board check: If the heater tests good but never energizes, the main control board relay may be faulty. This requires advanced diagnosis and likely board replacement.