Safety first: Turn OFF and unplug the machine. Allow the steam boiler to cool and depressurize. Open the steam wand to release residual pressure.

Steps to repair:

Check knob closure: Ensure the steam knob or lever is fully closed. Sometimes the knob can loosen and not fully actuate the valve.
Adjust packing nut: Slightly tighten the packing nut on the steam valve spindle to improve sealing. Do not overtighten, as this can make the valve hard to turn.
Disassemble valve: Remove the steam wand and valve assembly according to your model’s service instructions. Inspect the internal seat and Teflon seals.
Clean and descale: Remove scale from the valve body and spindle with descaler and a soft brush.
Replace seals: Install a La Marzocco steam valve rebuild kit (seals and gaskets). Reassemble and test for leaks.
Replace valve if necessary: If the valve body or seat is badly worn, replace the entire steam valve assembly.

Steam wand drips water or steam continuously even when the steam knob/lever is fully closed.

Possible Causes