the steam wand is stuck, i can't turn the knob to open or close it

Diagnosis

Milk or mineral scale has hardened inside the steam valve assembly, seizing the mechanism. This happens if the wand isn't purged and wiped after each use.

How to Fix It

You need to disassemble, clean, and lubricate the steam valve.

1. Unplug the machine and let it cool completely.
2. Remove the top cover and the front panel (if needed for access).
3. Unscrew the steam knob from the valve shaft.
4. Using a wrench, carefully unscrew the entire steam valve assembly from the boiler. Note the orientation of parts.
5. Soak the valve body and internal components in a descaling solution or hot water to dissolve deposits.
6. Reassemble with a light coating of heat-resistant grease (like Molykote 111) on the moving parts and threads.

If That Didn't Work

The valve stem itself might be corroded or damaged. In this case, you'll need to order a replacement steam valve assembly. Ensure you get the correct part for the Classic Pro (post-2015 model).

Heads Up

When reassembling, don't overtighten the valve into the boiler. Hand-tight plus a gentle quarter-turn with a wrench is sufficient. Overtightening can strip the soft brass threads in the boiler, which is a much more expensive repair.