La Marzocco Espresso Machine Error Code: Flow Meter 1 No Pulse
Flow Meter 1 No Pulse means the CPU does not receive the proper signal from the flowmeter, so water is not flowing through it. The manual says to press a button to silence the alarm, then call a service technician.
Medium: one group stops dosing, but the machine may keep running.
- Code
- Flow Meter 1 No Pulse
- Maker
- La Marzocco
- Equipment
- Espresso machines
- Applies to
- Linea PB and Strada AV
What does La Marzocco Flow Meter 1 No Pulse mean?
A flowmeter on each group counts the pulses that water produces as it flows, and the CPU uses them to dose the shot. If the CPU starts a shot and gets no pulses, it concludes that water is not flowing through the flowmeter and shows Flow Meter 1 No Pulse. The manual lists several reasons: coffee packed too tightly, a blockage in the tubes, a malfunctioning water pump, a defective valve or a damaged flowmeter. The first of these is the one an operator can influence. A basket that is overfilled or tamped too hard will not let the water through, so the flowmeter sees nothing. The alarm is silenced by pressing a button, and the manual then directs the operator to call a service technician.
Affected models and control systems
La Marzocco Linea PB (display software, Operating Manual V3.2) and Strada AV (MAN.16.1.01 V1.0). Boiler names and numbers on the display follow the machine's group and boiler count.
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
- Flow Meter 1 No Pulse on the display
- Alarm sounding
- Shot starts but no water or very little comes out
- Group 1 not dosing
Possible causes
Listed in La Marzocco's documentation
- Coffee packed too tightly
- Blockage in the tubes
- Malfunctioning water pump
- Defective valve
- Damaged flowmeter
Other likely causes — what usually sits behind Flow Meter 1 No Pulse on this control. A technician confirms which one it is before any part is replaced.
- Group screen or shower plate clogged with oils
- Water supply to the machine closed
- Flowmeter cable disconnected from the CPU
Safe checks before calling for service
- Press a button to silence the alarm, as the manual says.
- Check that the water supply is on and the filter is not blocked.
- Try a shot with a lighter, correctly tamped dose of coffee.
- If the alarm returns, stop using that group.
- Note which group and what the coffee dose and grind were.
How a technician diagnoses Flow Meter 1 No Pulse
- Read the message and confirm the group number.
- Verify water supply and pump pressure.
- Run water through the group without coffee and watch the flow.
- Check the valve and the tubes for blockage.
- Test the flowmeter signal and replace the failed part.
- Pump, valves and flowmeters run on line voltage inside the machine.
- Group water is hot and pressurized.
- A flowmeter needs a signal test.
How Flow Meter 1 No Pulse differs from similar codes
This alarm is about the flowmeter signal for one group. The boiler messages cover probes, heating and overheating.
Technical reference
- Maker documentation
- La Marzocco owner support
- Edition
- V3.2 - 12/2015 (La Marzocco S.r.l.)
- Models / control
- Linea PB and Strada AV
- Section
- Troubleshooting, printed pp. 104-105 (PDF pp. 104-105)
- 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 La Marzocco espresso machine error codes
Could my coffee dose cause it?
Yes. Coffee packed too tightly is the first cause the manual lists.
How do I silence it?
Press a button, as the manual says.
What if it comes back with no coffee?
Then the pump, valve or flowmeter needs a technician.
Need help with La Marzocco Flow Meter 1 No Pulse?
A technician confirms the cause on site and gives you the price in writing before any work starts.