E01 — Heating Circuit / Heater Relay Fault
Per Bosch's official US error-code page, E01 (grouped with E02) means the lint filter is blocked and needs to be cleaned. Bosch's instructions: clean the lint filter after each drying cycle. This is a simple maintenance step, not necessarily a heater/relay part failure — clean the filter first before assuming a component has failed.
- Keep using it?
- Limited use only
- DIY difficulty
- Moderate
- Verified against
- bosch-home.com ↗
How to fix it
- Unplug the dryer and wait 5 minutes before any service work.
- Pull the dryer out and inspect the vent hose and exterior vent for lint blockage — restricted airflow is the #1 root cause.
- Remove the back panel and locate the heater assembly (tall metal housing at the rear).
- Test the heating element across its terminals with a multimeter — should read roughly 10-15 ohms; OL means it's open and must be replaced.
- Test the thermal fuse and high-limit thermostat for continuity — replace any that read open.
- Inspect the heater terminal connectors for heat damage, melting, or carbon — replace the wire pigtail if scorched.
- If element and safety devices test good, the heater relay on the main control board has likely failed — replace the control module.
- Reassemble, restore power, and run a timed dry cycle to verify heat returns within 2 minutes.
Why it happens
Typical signs: No heat during cycle · Clothes still wet at end of cycle · Cycle runs full time but cold · E01 displayed at end of cycle
- Failed heating element Open coil in the heater assembly — no continuity across the element terminals.
- Stuck or failed heater relay on control board Relay on the main PCB welded closed or burned open, common after voltage spikes.
- Tripped thermal fuse or high-limit thermostat One-shot fuse opens permanently after an overheat event, usually caused by restricted venting.
- Loose or burned wiring at heater terminals Spade connectors at the element discolor and lose contact over time.
- Failed temperature sensor (NTC) giving bad reading Board disables heat when it sees impossible temperature values.
Parts you may need
If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.
More Bosch dryer codes
Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: bosch-home.com.