Black specks from water wand - La Marzocco GS/3 MP

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
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#1: Post by mgrayson »

GS/3 MP about 3 years old. I noticed some black specs in the tea water recently. Since I'd had a vacuum breaker fail and an o-ring dissolve, I thought it might be residue from that. I drained the steam boiler twice. The first time there were a lot of black flakes in the bucket. After the second time, the speck were reduced to maybe one visible per cup of hot water. But then a week later, I'm seeing more of them.

The group head produces specks, but they are obviously coffee.

Is this a sign of impending doom? Common, inevitable, and harmless? Somewhere in between?

Any advice gratefully accepted,


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#2: Post by HB »

Scale buildup? Heating element? To inspect directly, you could use an inexpensive bore scope camera connected to your phone.

From Inexpensive scope camera
Dan Kehn

mgrayson (original poster)
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#3: Post by mgrayson (original poster) »

One borescope later, and here's what I find in my steam boiler. This alien fungus is on the top. Everything else is, to the best of my discernment, pretty clean.

Descale? Nuke it from orbit? Call a priest?


Here are some more pics now that it's cooler in there