Breville / Sage Barista Touch Impress ER04: temperature sensor short circuit
ER04 means: Ferro heater temperature sensor short circuit detected during operation.
How to fix ER04
- 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 ThermoJet (ferro) heater 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 ThermoJet (ferro) heater 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
Unplug the machine. Press and hold the Power button while plugging it back in. When the password screen appears, enter 02015 to open Service Mode, then open the error log.
Clear the log after a repair so you can tell whether the fault has really gone.
Related codes on the same part
- ER01 — Ferro heater temperature sensor open circuit detected at startup
- ER02 — Ferro heater temperature sensor open circuit detected during operation
- ER03 — Ferro heater temperature sensor short circuit detected at startup
Same fault on other Breville / Sage machines
FAQ
What does ER04 mean on the Breville / Sage Barista Touch Impress?
Ferro heater temperature sensor short circuit detected during operation. The ThermoJet (ferro) heater 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 happened during operation, heat or steam getting at the connector is the prime suspect.
Can I fix ER04 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 ThermoJet (ferro) heater 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 ER04?
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 BES881; fixes follow documented repairs and owner reports. Model revisions can differ. If your appliance is under warranty, contact the manufacturer before opening it.