Here is my hot water tap:
I have not been able to to figure out why the hot water coming from the hot water tap on my La Cimbali M30 is flash boiling. I have another La Cimbali M30 that does not have the same problem as the water is hot but does not splatter all over your hands and burn you. I took the nozzle from the good machine and put it on the M30 that is flash boiling and it made no difference.

The water line goes directly to the boiler where it meets some kind of valve that appears to inject fresh cold water with water coming from the boiler. The screw like valve was stuck in place so I replaced the inside part of the valve with a new one.
Last night was the first time I was able to adjust the valve and turn it while hot water was flash boiling out of the hot water tap. Adjusting the valve has not solved the problem. Does anyone have any idea why adjusting this has not fixed the flash boiling?

Thank you for the help,
Craig

Has anyone experienced this before?

I haven't seen this particular model, but my La Marzocco Strada has a similar mixing valve for the hot water tap. It also has a programmable feature to enable/disable the pump while drawing water, so you can pick between a mix or only steam boiler water (e.g., if you're only using it for cleaning portafilters and such).

Back to your opening post:

ontum wrote:The water line goes directly to the boiler where it meets some kind of valve that appears to inject fresh cold water with water coming from the boiler.

Judging from the video, it looks like either there is no incoming fresh water into the mixing valve, or the pressure of the incoming water is so low, the resulting water flow is 98% steam boiler water. How is water supplied to the mixing valve, i.e., mains pressure or by the pump? If by the pump, is it possible there's a solenoid or stuck check valve preventing incoming water from reaching the mixing valve? Just a guess.

HB wrote:I haven't seen this particular model, but my La Marzocco Strada has a similar mixing valve for the hot water tap. It also has a programmable feature to enable/disable the pump while drawing water, so you can pick between a mix or only steam boiler water (e.g., if you're only using it for cleaning portafilters and such).

Back to your opening post:


Judging from the video, it looks like either there is no incoming fresh water into the mixing valve, or the pressure of the incoming water is so low, the resulting water flow is 98% steam boiler water. How is water supplied to the mixing valve, i.e., mains pressure or by the pump? If by the pump, is it possible there's a solenoid or stuck check valve preventing incoming water from reaching the mixing valve? Just a guess.

Great news. I finally got around to taking lines off the solenoid that supplies cold water to the hot water mixing valve. As soon as I took the incoming water line off the solenoid I instantly realized what was wrong.

There is a jet/screen combination piece in the connection nut in between the water line and valve. I had run the machine without an incoming water filter for a time and it appears some junk has restricted the screen enough to prevent a substantial amount of cold water to pass.

I removed the screen temporarily and that did it. Problem fixed. What a relief. Thank you for the help.

-
Craig