Display shows “Err1” and the kettle or coffee maker will not start heating.

Safety first: Unplug the unit and allow it to cool completely (at least 15–20 minutes) before any inspection.

• Check for water: Ensure the kettle or internal boiler is filled to at least the minimum fill line. Fellow electric brewers and kettles (e.g., Stagg EKG, Corvo, Clara Electric) must never be run dry.
• Power cycle: After cooling, unplug for 60 seconds, then plug back in and try again with water filled correctly.
• Descale the heating surface:
  • Fill the kettle or reservoir with a 1:1 mix of white vinegar and water up to the max line.
  • Heat to near boiling, then power off and let sit 20–30 minutes.
  • Discard solution, rinse thoroughly 2–3 times, and wipe the stainless base plate with a soft cloth.
• Inspect base and contacts: Check the power base contacts for burnt marks or debris. Wipe with a dry cloth only; do not use liquids on the base.
• If Err1 persists: The thermal fuse or NTC temperature sensor may be damaged. Replacement requires opening the kettle body and should be done by a qualified technician or through Fellow support.