The Aurelia II will show a specific message on its display when something goes wrong. Most are not stop-everything emergencies, but a few are. Here’s what each one means and whether you can finish service or need to shut down now.
The full list of display messages and what they mean
The Aurelia II groups its alarms into a few categories. I’ll go through them by how urgent they actually are in a working cafe.
MAINTENANCE ALARM
This one’s just a reminder. The machine tracks elapsed time or shot count, and this fires when you hit the interval set in the menu. Go to Menu > Maintenance, adjust the date or cycle number, and press reset. You can keep pulling shots. Don’t ignore it for weeks, though.
BATTERY ALARM
The electronic control unit uses a CR2032 coin cell (on Digit and T3 versions) to power the clock and hold meter data when the machine is off. This message means replace it soon. It won’t stop the machine mid-service, but if you lose power before swapping it, you may lose meter and date/time data. A tech can swap it in minutes.
GROUP DOSE ERROR
The flowmeter on that group stopped sending pulses within 3 seconds of a pour starting. Either the flowmeter is failing, or the wiring to it has a problem. The machine won’t dose correctly. Stop using that group and either pull from another group or call a tech. Continuing to use it means your shots will be inconsistent at best, completely wrong at worst.
GROUP POUR ERROR
A delivery ran longer than 240 seconds without stopping. The machine’s safety timer kicked in. This usually points to a stuck or failed flowmeter, a solenoid that didn’t close, or a control board input issue. Don’t use that group until it’s diagnosed. An open solenoid running water for four minutes can cause a mess and potentially damage the machine.
PRESSURE ERROR
The boiler pressure switch detected pressure above 1.60 bar. The heating element shuts off automatically. If pressure drops and the machine recovers, note the incident and monitor it. If this happens repeatedly, the pressure switch or the heating element is suspect. Repeated PRESSURE ERROR with no recovery is a shut-down-now situation. Running a boiler at unsafe pressure is a real hazard.
LEVEL ERROR
The auto-level timed out. With the pump running, the machine expects the boiler to fill within 90 seconds; without the pump, the limit is 180 seconds. If it can’t reach the right level in that window, it throws this alarm and stops the pump and heating element. Most likely cause is a failed level probe, a water supply issue, or a weak pump. Don’t keep trying to restart and force it. Call someone.
BOILER PRESSURE SWITCH ERROR
Different from PRESSURE ERROR. This means the pressure switch sensor itself has a fault, not that the pressure is out of range. The display will show CC (short circuit) or NC (not connected/open circuit) to indicate what kind of fault. The machine may not be able to read boiler pressure accurately, which means it can’t protect itself correctly. Treat this as a call-a-tech-today situation.
GROUP PROBE X ERROR / BOILER PROBE X ERROR
These mean the temperature sensor on group X (or boiler X on a multi-boiler machine) has a problem. The display will also show either “CC” (short circuit, probe wires touching somewhere they shouldn’t) or “NC” (probe is disconnected or has failed open).
Either way, the machine is flying blind on that group’s temperature. Shots will be inconsistent, possibly badly under-extracted if the group runs cold. Stop using the affected group. Probe replacement is straightforward for a tech.
CC STEAM PROBE 1 / 2 ERROR
The steam wand temperature sensor has a short circuit. When a steam probe fails this way, the machine falls back to timed steam mode rather than temperature-controlled steam. Your milk texturing will be inconsistent. It’s not an emergency stop, but the quality hit is real and the probe should be replaced.
CUP WARMER PROBE 1 / 2 ERROR
The cup warmer temperature sensor has failed (CC = short circuit, NC = disconnected). The cup warmer may run without temperature control. Low urgency for service, but worth fixing on a scheduled visit.
EEPROM WRITE ALARM / RTC READ ERROR / RTC WRITE ERROR
These are control board memory and clock errors. EEPROM errors mean the board couldn’t save settings or meter data. RTC errors mean the real-time clock has a read or write failure. Any of these, or if they persist after a power cycle, points to a failing control board. The machine may still pull shots but is losing data. Get a tech to evaluate the board.
SERIAL COMS ERROR
The control board and the display aren’t communicating cleanly. Could be a loose ribbon cable, could be interference, could be a failing board. If it clears on a restart, note it. If it keeps coming back, the board or cabling needs inspection.
ERROR: NON-COMPATIBLE CONTROL UNIT
This one appears when a control board doesn’t match what the rest of the machine expects. Usually shows up after a repair where the wrong board version was installed, or after a firmware update mismatch. Not a field fix.
What a tech actually checks
When I look at an Aurelia II with a probe error, the first thing I do is check the connector at the probe itself, then trace the cable back to the control board. A lot of “GROUP PROBE NC” errors are just a connector that vibrated loose over time. For LEVEL ERROR, I’m checking water pressure at the inlet, the level probe continuity, and pump output. For PRESSURE ERROR repeats, I’m testing the pressure switch and inspecting the heating element.
The machine’s error logging is actually pretty good. If you can tell me which alarm, which group number, and roughly how often it fires, that narrows the diagnosis significantly before pickup.
What’s safe to do yourself
You can reset a MAINTENANCE ALARM through the machine’s maintenance menu. You can power cycle once if you get a one-time SERIAL COMS ERROR or LEVEL ERROR to see if it clears. That’s about it.
The BATTERY ALARM is easy to dismiss because the machine keeps running, but the cell swap involves getting into the electronics enclosure. Let a tech handle it on a scheduled visit rather than risk losing your settings or introducing a connection issue.
What you shouldn’t do: ignore PRESSURE ERROR repeats, keep using a group throwing PROBE or DOSE errors, or try to bypass the safety shutdowns. The machine’s alarms exist because something is actually wrong.
Call us
LEVEL ERROR, BOILER PRESSURE SWITCH ERROR, or PRESSURE ERROR that won’t self-clear means call us right away. GROUP PROBE errors on multiple groups, or any alarm that keeps coming back after a restart, warrant the same urgency. A single CUP WARMER PROBE or BATTERY ALARM can wait for a scheduled visit.
Diagnostics can take up to a week; most repairs run 3–4 weeks. That is exactly why we recommend preventive maintenance: a maintained machine does not sit in a repair queue for a month.