I just became co-owner of a Rancilio Z11 omicron 2-group. A little departure from antique home-lever land, but I want to get it running. I don't even understand the very basics, e.g. what does the pump do? Can anyone give me a brief synopsis of how a commercial machine like this works?

Is the group fed by pump pressure? I assume its a HX group.

Does the brew water come directly from the tap, with the boiler used for steaming and HX to the groups?

The machine looks just like this, and appears to be in good shape:

Rancilio Z11 Omicron Tune Up

Thanks,
PC

I can give you a basic overview if you would like, but you may find that the Rancilio Manuals may be a better read.


Edit: Or maybe not, that is some crazy translation work there.

I was looking through the Z11 users manual and I ran across this unusual looking part...



Adapter for 50g and 80g baskets. Has any one seen one of these in the wild?

-Cecil

Congrats on the new acquisition! We've been running an early model Z11 in our shop for 5 years and we love it. It is built very solidly, and aside from the usual maintenance upkeep it really has been unstoppable.

It sounds like you have the right idea as to how it works. Yes the groupheads operate from the pump, which is why the pump has it's own connection from the machine. And you are correct on the water paths as well. Brew water comes through the HX from your water source and steam from boiler etc.

have fun
#222

Yes, I had the top off tonight for a few minutes. It looks quite good, other than some scale around two nuts, one around one of the nuts from the boiler to the HX line, and another at one of the HX connectors to the group. I guess these developed small leaks at some point, so they got some corrosion These should be easy to fix.

So, unless there are some electronics issues, it should just need a cleaning and a couple of fittings.

Do you normally just pull shots with the on-demand button, or do you try to program the set-volume buttons?

Most interesting is the two-doubles with one PF button. Sounds like a one-way ticket to overextraction. Here is Sweden its actually common, if one makes the mistake of asking for two double espressos, to have the "barista" put two cups under one PF and fill them both!

It came with a Rancilio Pro-con pump. I suppose this plugs into the machine, and turns on when the brew buttons are pushed?

And the HX is just fed by passive boiler pressure, or does it also run off the pump.

Once I get it running is the espresso going to be any better than that from my home levers?

Thanks,
PC

Now, if I could only trade it for one of these:

http://www.rancilio.com/rancilio/pop_pr ... 1&pg=group

peacecup wrote: Do you normally just pull shots with the on-demand button, or do you try to program the set-volume buttons?

In my use I use the manual dosing button, if you were in a busy working environment you can program each button to what ever volume you want. I do have one button programmed for a long flush and one for a short flush though.

peacecup wrote: It came with a Rancilio Pro-con pump. I suppose this plugs into the machine, and turns on when the brew buttons are pushed?

The controller board will turn the pump on both for boiler fill and for shot pulling.

peacecup wrote: And the HX is just fed by passive boiler pressure, or does it also run off the pump.

The HX's (there is one HX for each group) are pump fed, there is a relay valve that directs the flow from the pump to either boiler fill or to the flow meter/hx/group.

peacecup wrote: Once I get it running is the espresso going to be any better than that from my home levers?

There is better and there is different. I use my La Peppina and my S-27 as both make great coffee, but different coffee.

On the other hand any of the commercial Rancilio machines will not blink at pulling 45 shots per hour nonstop and each one will be amazing. There is a learning curve here, mostly when you are going from idle. These are not dragons, more in the balanced range, so once you flush to get a bit of heat up in the group you can just crank them out.

From idle I will use the flush and go method, once I see the head temp peak at about 216 it will begin to drop I stop at about this point, this is maybe 3-4 seconds after the steam flash, lock the preloaded shot and pull without any delay. The flush for following shots are just enough to flush the screen, maybe a second or two.

If you don't trust your taste buds for learning the temp surf the heads have a spot all ready to drop in a thermo-probe.

Also those Class 6 LE machines are just sexy. They just make you want to grab its lever.

-C