Thanks all for the ideas:
Eric N.: I try hard not to suck any milk into the steam wand and purge it before and after use so???
Next time it shows up I'll take a picture and also try to drain it through a bit of filter paper so to have a sample but then what? Is there a cheap way to test it? If it is milk residue is there some "stuff" I could dose it with for a color change? Probably not worth the expense of sending it off to a lab. Remember the SyFy movie "Quatermas 2"? I don't think this stuff is going to get up an crawl though my house so maybe it is unimportant.
KDM

HB wrote:sight glass (n): A transparent tube or window through which the level of liquid in a reservoir or supply line can be checked visually.

That was very helpful. Thanks!

duke-one wrote:Thanks all for the ideas:
Eric N.: I try hard not to suck any milk into the steam wand and purge it before and after use so???
Next time it shows up I'll take a picture and also try to drain it through a bit of filter paper so to have a sample but then what? Is there a cheap way to test it? If it is milk residue is there some "stuff" I could dose it with for a color change? Probably not worth the expense of sending it off to a lab. Remember the SyFy movie "Quatermas 2"? I don't think this stuff is going to get up an crawl though my house so maybe it is unimportant.
KDM

Kenneth,
It is something in the water source, or something getting into the boiler. are you using a water filter/softener cartrage setup? have you tested you water?
BTW I have had 2 lineas at home as well as a FB80. great machines!

Eric

Eric: I have great water to start with (EBMUD in Berkeley Caifornia) and use a dual Ever Pure set up with MC2 cartridges from the day the new Linea was installed so I think that would preclude anything in the supply. By the way I ran the Astoria for 15 years with no filter at all and had no known water troubles. Maybe I should run this by L.M. to see what they know. Other Linea owners on H.B. have mentioned similar "stuff".
Duke

I have heard from L.M. tech support that the problem "may" be the MC2 cartridge is at fault:
MC2 everpure filter is a polyphosphate softening filter designed for fountain beverage systems. If your filter is indeed using polyphosphate I would not be surprised of some fluffy substance in your steam boiler. Polyphosphate is at its essence a calcium carbonate "lubricate" which prevents adhesion to tank walls at low temperatures, however nearing and above 212 degrees f polyphosphate breaks down and causes a fluffy build up.
Can anyone out there corroborate this? What cartridges do you use in your Everpure systems?
Duke

duke-one wrote:What cartridges do you use in your Everpure systems?

I don't use an Everpure system but a Bestmax filter from water+more. According to the marketing speak on their homepage the system supposedly is the "perfect solution for pure steam as a cooking medium in combi steamers and ovens" so one thinks it really shouldn't leave unsightly fluffy deposits at higher temperatures, but I still have them in my steam boiler...

This is what Pentair (Everpure) said:

MC2 does not have a scale inhibitor. It would interfere with the carbonation if used for soft drinks. (There are other uses for this cartridge)

For espresso you can use a combination filtering and softening system. The MC2 goes in the first position to filter chlorine tastes and odors etc and a 7SO softening cartridge goes in the second position to remove some for the hardness minerals that would cause scaling. It is important to use a Twin-Series head with this setup.

As I have said I have a lot of money in the current filter system, so I don't mind an early filter cartridge change to get the right functions but I'm not going to put a different system in.
Duke



????????

I don't think anything is going to keep your site glass absolutely clear. I've had my Linea for about 7 years (I'm guessing) and I have to drain the boiler and remove the site glass and clean the whole site glass area about once a year. You need to buy the site glass wrench (well, you don't need to buy one, I've seen members build their own but I would recommend you buying one) and a few extra gaskets. I end up replacing the glass every couple of years too.

Just a part of owning one of the best!!

Magnus/Mitch: Thanks for the support, at this point I just want to get the right filter cartridges in my system. I've now had somewhat contradictory info from L.M. and Everpure as the last few of my posts show. The flushing is not a big deal and as Mitch says once yearly (or so) pulling of the sight glass for a through cleaning is also do-able. I have $500, more or less, in the filter system so it is staying albeit with possibly a new cartridge or two.
Duke

Well, I've made a few mistakes at least according to Everpure customer service.
First I should have used a "series" head instead of the "parallel" one I bought; the QC71. This means the water flows through both filters at the same time instead of first through one then the other. With this setup I was told to use two of the same cartridges. I had my local water report and quoted the hardness (13-31 mg/L as CaCO3) to the rep and was told to use 6SO or 7SO cartridges. Putting this info with the other posts above from L.M. and Everpure I think I'll replace my MC2's with the 7SO's and keep observing the sight glass for "tan fluffy stuff".
Duke