Breville / Sage Dual Boiler 03: temperature sensor short circuit
03 means: Coffee boiler temperature sensor short circuit.
How to fix 03
- Switch off at the wall and unplug. Leave the machine for an hour so any moisture in the connectors dries, then try again. A short that clears after drying tells you there is a leak to find.
- Open the machine (base or rear panel) and inspect the coffee boiler temperature sensor (NTC) plug and the wiring near the boiler. Look for a wet patch, white scale trails or a perished o-ring around the probe.
- Replace any leaking o-rings at the boiler fittings and NTC probes. Kits are cheap and the leak, not the sensor, is often the true fault.
- If the code persists after everything is dry, replace the coffee boiler temperature sensor (NTC).
- Clear the error log and run the machine through a full heat-up and a shot to confirm.
When to stop and call a repairer
If you see scorch marks on the triac board or the machine trips your GFCI / RCD, stop: that is an electrical fault, not just a sensor.
What it costs
Parts: Genuine NTC sensor assemblies run about $25 to $95 depending on which sensor it is (steam wand and milk-jug sensors are the dear ones). O-ring kits are $10 to $20.
Service: Out-of-warranty Breville service quotes for internal faults are commonly $300 to $500, sometimes more, plus shipping. Independent espresso repair shops are usually cheaper for a sensor swap.
Worth repairing? Yes in most cases. Sensor plus o-ring kit is well under $100. If a leak has soaked the control board, get a quote before spending anything.
How to check the error log
Switch the machine off at the wall. Hold EXIT and MANUAL while switching the power back on to enter the self-check menu. Press MENU to reach item 3 (error log) and item 4 (boiler level status such as LLL / HHH). In the error log, MENU steps through codes 00 to 12 with a count for each. At "ErSt", hold MANUAL until it beeps to clear the codes (the cup counter is not reset).
Clear the log after a repair so you can tell whether the fault has really gone.
Related codes on the same part
- 02 — Coffee boiler temperature sensor not detected
FAQ
What does 03 mean on the Breville / Sage Dual Boiler?
Coffee boiler temperature sensor short circuit. The coffee boiler temperature sensor (NTC) is reading as a short circuit: the board sees near-zero resistance, which a healthy sensor never produces. The two real-world causes are water bridging the sensor contacts (a leak or steam at the probe seal) and a failed sensor. Because it failed at startup, it is usually a wet connector or a sensor that has already died.
Can I fix 03 myself?
DIY difficulty: moderate. Switch off at the wall and unplug. Leave the machine for an hour so any moisture in the connectors dries, then try again. A short that clears after drying tells you there is a leak to find. Open the machine (base or rear panel) and inspect the coffee boiler temperature sensor (NTC) plug and the wiring near the boiler. Look for a wet patch, white scale trails or a perished o-ring around the probe.
How much does it cost to fix 03?
Genuine NTC sensor assemblies run about $25 to $95 depending on which sensor it is (steam wand and milk-jug sensors are the dear ones). O-ring kits are $10 to $20. Out-of-warranty Breville service quotes for internal faults are commonly $300 to $500, sometimes more, plus shipping. Independent espresso repair shops are usually cheaper for a sensor swap.
Is it worth repairing?
Yes in most cases. Sensor plus o-ring kit is well under $100. If a leak has soaked the control board, get a quote before spending anything.
Code meanings are compiled from manufacturer service references and repair documentation for the BES920; fixes follow documented repairs and owner reports. Model revisions can differ. If your appliance is under warranty, contact the manufacturer before opening it.