Machine displays ER01 and will not start extraction or heating

Safety first: Unplug the coffee maker and allow it to cool for at least 60 minutes before opening any panels. Never work on a hot thermocoil or boiler.

ER01 on many Sage espresso machines (e.g. Barista Express, Barista Pro, Dual Boiler) indicates an over-temperature or thermal fuse issue.

• Power reset: After the machine is fully cool, plug it back in and power on. If ER01 clears temporarily but returns when heating, suspect a sensor or scale issue.
• Check for blocked water flow:
  • Remove the water tank, rinse it, and ensure the intake filter is not clogged.
  • Run a descale cycle if the machine will allow it, using Sage-approved descaling solution. Heavy limescale in the thermocoil or steam boiler can cause localized overheating.
• Inspect for obvious overheating signs (advanced users):
  • Remove the top cover (if you are comfortable and warranty has expired).
  • Locate the brew thermocoil and thermal fuse assembly.
  • Look for burnt insulation, discoloration, or a blown thermal fuse capsule clipped to the thermocoil.
• Do NOT bypass the thermal fuse: If the thermal fuse is open, the safe repair is to replace it with the correct temperature and rating part, not to bridge it.
• When to call a technician: If ER01 appears immediately on power-up, or if you confirm the thermal fuse is open, the safest option is to have a qualified technician replace the thermal fuse and check for underlying overheating causes (blocked thermocoil, failed triac, or stuck relay on the control board).