Breville espresso machine shows ER02 and does not heat or brew.

Safety: Unplug the machine and let it cool completely before removing any covers.

Basic user checks:

• Power cycle: Unplug for 5 minutes, then reconnect and power on. If ER02 appears immediately, the control board is not seeing a valid temperature signal.
• Check for moisture: Inspect around the water tank and top vents for signs of leaks that may have dripped onto electronics. Dry the exterior thoroughly.
• Factory reset (if model supports it): Perform a factory reset per the user manual to rule out a software glitch.

Advanced checks (experienced users only):

• Remove the top cover and locate the NTC temperature sensor attached to the thermoblock or boiler.
• Inspect the sensor plug and wiring harness for corrosion, loose fit, or broken insulation. Reseat the connector firmly.
• Use a multimeter to measure resistance across the sensor leads. A completely open or near-zero reading indicates a failed sensor.

Resolution: Replace the NTC temperature sensor with a Breville-compatible part if it is open/shorted. If the sensor tests good but ER02 persists, the main control PCB may be faulty and should be diagnosed or replaced by a technician.