Nuova Simonelli Aurelia II Message COARSE GRINDING: Shots Running Fast
COARSE GRINDING on a Nuova Simonelli Aurelia II (Digit, V and S) is a coffee setting message, not a breakdown. It shows when the delivery time is much shorter than the set values, so the grind is too coarse and water runs through the coffee too fast. Change the grinding degree to a finer setting and press the key to clear the message.
Low: an operator prompt about the grind; the machine keeps running.
- Code
- COARSE GRINDING
- Maker
- Nuova Simonelli
- Equipment
- Espresso machines
- Applies to
- Aurelia II Digit / V / S
What does Nuova Simonelli COARSE GRINDING mean?
The Aurelia II measures every delivery. The doser counts the water and the control also times the shot, and it compares the time with the values that were set for that key. When a delivery finishes much faster than those values, the control concludes that water is passing through the coffee bed too easily and shows COARSE GRINDING. It is a prompt about the coffee, not a report of a failed part. A bed that is too coarse, too lightly dosed or tamped too softly offers little resistance, so the shot runs fast and tastes thin and sour. The machine is working as it should, and the cure is in the grinder setting. The handbook points to the grind setting on the grinder, the dose size and tamp pressure, worn burrs in the grinder and, less often, pump pressure that runs too high. Because a grinder drifts through the day with temperature and humidity, baristas often meet the message in the first hour after a restart or after changing beans. Treat it as a cue to adjust and taste, not to call for service.
Affected models and control systems
This applies to Nuova Simonelli Aurelia II machines in the Digit, V and S versions (User Handbook, March 2012).
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- COARSE GRINDING shown after a shot
- Shots finishing much faster than the set time
- Thin, pale or sour espresso
- Crema that vanishes quickly
Possible causes
Listed in Nuova Simonelli's documentation
- Grind set too coarse for the dose
- Dose size too small or tamp pressure too light
- Grinder burrs worn
- Pump pressure running too high
Other likely causes — what usually sits behind COARSE GRINDING on this control. A technician confirms which one it is before any part is replaced.
- Grinder setting drifting after a bean change or a damp morning
- Hopper nearly empty, so the dose weight falls
- Burrs dull enough that fines are missing from the grind
Safe checks before calling for service
- Change the grinding degree to a finer setting, as the owner's manual directs.
- Press the key to clear the message.
- Pull another shot and check the timing.
- If shots stay fast after a finer grind, call us and tell us the grind setting, the dose and how old the burrs are.
How a technician diagnoses COARSE GRINDING
- Read the message and the set delivery time for that key.
- Check the grind, dose and tamp with a scale and timer.
- Inspect the grinder burrs for wear.
- Measure pump pressure at the group with a gauge.
- Adjust the pump or replace burrs only after these checks.
- Pump pressure is adjusted inside the machine, where hot parts and live wiring are close.
- Burr replacement and grinder alignment need the right tools.
- Pressure readings at the group need a test gauge and a trained eye.
How COARSE GRINDING differs from similar codes
FINE GRINDING is the opposite message, for shots that run too slowly.
Technical reference
- Document
- Aurelia II (S, V, Digit) User Handbook March 2012, Function Messages p.75-78
- Edition
- March 2012 (Marzo 2012); no part number printed
- Models / control
- Aurelia II Digit / V / S
- Section
- 10. Aurelia Digit Machine Function Messages, p. 75-76 (messages listed as DIAGNOSIS OF ERROR, DELIVERY ERROR, DOSER ERROR, LEVEL ERROR, PRESSURE ERROR, OVERCURRENT ERR., FINE GRINDING, COARSE GRINDING); 11. Aurelia V, p. 77; 12. Aurelia S, p. 78
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Nuova Simonelli espresso machine error codes
Is COARSE GRINDING a machine problem?
No. It is a coffee message, and a finer grind usually fixes it.
Why does it come back each morning?
Grinders drift with temperature and humidity, so small daily adjustments are normal.
When should I call?
If shots stay fast after a finer grind and a firm tamp, the burrs or pump pressure need a look.
Need help with Nuova Simonelli COARSE GRINDING?
A technician confirms the cause on site and gives you the price in writing before any work starts.