Applies to: Dual Boiler.
How to fix 02
- Switch the machine off at the wall, wait 60 seconds and switch it back on. A one-off reading glitch clears; a real open circuit comes straight back.
- Reaching the coffee boiler temperature sensor (NTC) plug means opening the machine, which is technician work. A technician would check that plug on the control board for corrosion or heat marks and test the sensor circuit. Tell them the code you see.
- Look under and around the machine, from the outside, for water trails. Moisture on a connector can read as an open or short circuit; a technician would find and fix the leak behind it, often a boiler o-ring or hose clip.
- If the code returns, the coffee boiler temperature sensor (NTC) or its wiring needs replacing by a technician.
- Afterwards, clear the stored error (see how to read the error log below) so you can tell whether it recurs.
When to stop and call a repairer
Stop and book service if you see water leaking, a burning smell or any scorch marks. Do not open the machine yourself.
What it costs
| Parts | Not published by Breville. Ask an authorised service centre for a quote. |
|---|---|
| Service | Not published by Breville. Ask an authorised service centre for a quote. |
| Worth repairing? | Often yes for a single sensor, but Breville does not publish repair costs. Get a quote first, especially on an older machine. |
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. Technician videos say it shows boiler level status (such as LLL for low and HHH for high) and temperatures in the order coffee boiler, steam boiler, group head. The same videos say the stored error codes (00 to 12, with a count for each) sit in a separate engineer menu, opened by holding 1 CUP and 2 CUP and pressing the power button. Breville does not document either menu, so treat these steps as unconfirmed.
Clear the log after a repair so you can tell whether the fault has really gone.
Beyond the fix
Tips and tricks
- In the hidden self-check menu, compare the three temperature screens. A reading near room temperature, or far from the other two, points at a sensor or connector before any parts are bought.technician video
- Look for steam or wetness around the machine's inside during use, and for a lid that stays warm when switched off. Leaks above the control board are a known cause of odd sensor and heater faults; a technician fixes these.technician video
- Do not open the machine yourself to chase this. Mains voltage stays live inside even when switched off at the front, so book a qualified technician to test the sensor and its connector.technician video
Common mistakes
- Replacing the boiler or element first, when a sensor or connector on the temperature circuit is the cheaper thing to test.
- Skipping the self-check temperature readout, which separates the three heating circuits.
Further reading
Questions
What does 02 mean on the Breville / Sage Dual Boiler?
Coffee boiler temperature sensor not detected. The control board cannot read the coffee boiler temperature sensor (NTC). On this code the sensor reads as an open circuit: the wire has come off, the plug is loose or corroded, or the sensor itself has failed. Because it dropped out mid-cycle, a loose or heat-damaged connection is the most likely cause. Breville does not publish this code table, so the meaning comes from third-party service tables.
Can I fix 02 myself?
DIY difficulty: hard. Switch the machine off at the wall, wait 60 seconds and switch it back on. A one-off reading glitch clears; a real open circuit comes straight back. Reaching the coffee boiler temperature sensor (NTC) plug means opening the machine, which is technician work. A technician would check that plug on the control board for corrosion or heat marks and test the sensor circuit. Tell them the code you see.
How much does it cost to fix 02?
Not published by Breville. Ask an authorised service centre for a quote. Not published by Breville. Ask an authorised service centre for a quote.
Is it worth repairing?
Often yes for a single sensor, but Breville does not publish repair costs. Get a quote first, especially on an older machine.
When does 02 typically show up?
Breville / Sage Dual Boilers report 02 any time. There is no reliable pattern to when it appears — treat any occurrence as real.
Can I keep using the machine with 02 showing?
Usually you can finish the drink you are making, but do not ignore it — the underlying fault rarely heals itself. Work through the cheap checks first.
Will 02 clear on its own?
Rarely. A reset or power cycle is worth one try, but 02 with a "hard" difficulty rating almost always means a failed component that has to be replaced.
How long does the repair take?
This one is a bench repair for most owners — the teardown, test and reassembly are the bulk of the work, not the part itself.