Dryer stops mid-cycle and displays E04; often accompanied by poor drying performance

Safety first: Disconnect power before removing panels or the condenser unit.

• Clean lint filters: Remove all accessible lint filters (door filter, base filter, and any additional Siemens fine filters). Wash with warm water and dry completely before refitting.
• Clean condenser: On condenser and heat pump Siemens dryers, open the condenser flap, remove the condenser unit, and rinse it thoroughly from the back side with warm water until water runs clear. Allow to drain and dry before reinstalling.
• Check exhaust duct (vented models): Detach the exhaust hose and clear any lint build-up. Inspect the wall vent and external flap for obstructions.
• Inspect thermal cut-out: Access the heater housing and locate the manual-reset or one-shot thermal cut-out. If it has a reset button, press it gently. If it is a one-shot fuse and shows no continuity, replace it.
• Prevent recurrence: Ensure the dryer has adequate ventilation around it and that filters are cleaned after each cycle. If E04 returns quickly, a deeper airflow or control issue may require a technician.