It's been one year since my La Marzocco GS/3 paddle machine arrived. I think it was one of the first post-"fire sale" machines to arrive in the U.S. and was certainly one of the first GS/3 paddles. So, considering all the problems that were reported with the earlier machines, I thought it would be useful to report on my experience in the last 12 months with this newer version.

Its typical usage is 3 or 4 doubles a day, with my wife frothing milk for her tea another 3 or 4 times. The machine sits next to a sink, so I don't use the water spout for anything other than occasionally pre-heating a cup from the cool side of the cup tray.

I am happy to say that the one and only issue has been the gradual failure, starting at about 6 months, of the steam boiler expansion valve [CORRECTION: "vacuum breaker"]. Thankfully, it is an inexpensive part to replace.

The water still flows at 500ml/min. through the gicleur. So, I assume my water treatment (Everpure Claris) is doing its job.

No rattles developed, although I find, if I place the espresso cup in just the right position below the portafilter, the harmonics of the drip tray cover can sometimes develop an audible buzz. When I move the cup, it stops.

What the difference is from this essentially problem-free machine to the fire sale machines, I can't say for sure, but I suspect that sitting unused in a warehouse for months with the remains of their test water didn't do them any good.

I hope the people who bought them have been able to resolve their problems one way or another.

so, how goes the pressure profiling with the paddle group?
Be interesting to here if it was worth all the fanfare?

Yeti wrote:so, how goes the pressure profiling with the paddle group?
Be interesting to here if it was worth all the fanfare?

Since there are only two options, line pressure or pump, I don't think I would call it "pressure profiling." More like "pressure choice." My current habit is to preinfuse at line pressure for 6 seconds, run it until blonde at pump pressure and occasionally "save" a shot by moving back to line pressure, if it starts to gush prematurely. Does that produce a better cup than the non-paddle? I dunno.

In hindsight, are you happy you chose this machine?

Tom_MN wrote:In hindsight, are you happy you chose this machine?

Delighted.

Yeti wrote:so, how goes the pressure profiling with the paddle group?
Be interesting to here if it was worth all the fanfare?

I would propose that this machine offers as much pressure profiling capability (regulated line pressure vs. pump pressure), as is likely to be shown to be useful, in the future. It is manual, however, and probably not going to be repeatable from shot to shot in this machine.

Like Marshall, I would also propose that this manual "profiling" is practical and useful in actual use, however the improvement it offers in the cup is debatable. I do have many years of experience with various methods of "preinfusion," in comparison to the immediate 9 bar pressure "assault" of a machine such as the Cimbali DT1 Rotary Junior, and there is no question that without some sort of gradual pressure rise at the start of a shot that one will have a much less forgiving machine and a much higher percentage of sink shots, especially if updosing. Whether those shots that are acceptable after an immediate 9 bar "pressure assault" are different or inferior to those produced with a gradual pressure rise (e.g. "preinfusion") is anybody's guess.

ken

I think the specifics of the machine play into the preinfuse or not debate. Some machines simply work better with it than others. I had an old Faema two group that was a beast to work with. I added a delay on make relay to the rotary pump so I could infuse using line pressure before the pump kicked in. That made a very noticeable difference on that machine. My Elektra A3 ramps to full pressure in around 3 seconds (maybe a little less) but has been very easy to work with. I have been asked by several people why I do not make a similar change to my current machine. The simple answer is it just does not need it, it works very good as is. Why try to fix something that is not a problem.

Good to hear the bugs have been shaken out of the GS3.

Marshall wrote:
I am happy to say that the one and only issue has been the gradual failure, starting at about 6 months, of the steam boiler expansion valve. Thankfully, it is an inexpensive part to replace.

The water still flows at 500ml/min. through the gicleur. So, I assume my water treatment (Everpure Claris) is doing its job.

I don't think you can come to this conclusion, Marshall, based upon the information you provided.

I assume you are writing about the vacuum breaker; I don't think there is an "expansion valve" in the steam boiler. That sort of valve is in the brew boiler, which is completely full of water under pressure, whereas the steam boiler is like what you find in HX and single boiler espresso machines, e.g. it is only partially filled with water and the rest is occupied by steam (when the machine is on and up to temperature).

The vacuum breaker is one of the first things in an espresso machine that will fail due to scaling minerals in the boiler water; I would expect the gicleur to fail later.

In addition, there is clearly a major difference in the water flow rates when an original GS/3 is compared to a paddle version, with the paddle having much greater flow (I typically measure around 550ml in my paddle, and I never got more than 450 in my original version GS/3, and usually less). The plumbing arrangement within the paddle machine is quite different than the original machine, however I don't understand how this can account for the flow difference. Based on this, I believe that the paddle machine is much less likely to have obstructions develop in the gicleur, but I could not explain to you why that is the case.

In any event, the most likely reason for the early failure of the vacuum breaker in your steam boiler was . . . . mineral deposition from the water you are feeding it with.

ken

Ken Fox wrote:In any event, the most likely reason for the early failure of the vacuum breaker in your steam boiler was . . . . mineral deposition from the water you are feeding it with.

As you'll recall, this was all hashed out last summer, with Shadowfax providing the most reasonable explanation (in my opinion):

As a counterpoint, Marshall, I have been using the same water filtration system as you (Claris) here in Houston, TX, and I also use the very best-available water testing equipment from Hach to make sure I'm in the proper range on hardness/alkalinity. For whatever reason I find that my GS3 spews a decent bit of water up the vacuum breaker valve when it turns on initially, leaving a lot of water over the valve to be evaporated off, leaving a residue of everything, not just the scaling minerals (which I have little of). It's worth noting that softening systems that don't reduce TDS (Claris is of this type) leave a lot in the water, and while this may not scale your boiler where it's in a closed, saturated-steam environment, the same rules do not apply in places where the water is fully vented and simply evaporates off. There, the water leaves behind much more right on bare metal and gaskets; having this issue on your breaker valve is *not* necessarily an indication that your machine is scaling internally.

See: Leave your La Marzocco GS/3 on

Marshall wrote:As you'll recall, this was all hashed out last summer, with Shadowfax providing the most reasonable explanation (in my opinion):

And that would be your opinion (and I guess also the opinion of Nicholas).

However, my own experience is not the same. In the dark ages, when I used to run my first Cimbali Junior off of the very hard tap water in my area, without any treatment other than the inadequate in tank softener in the pour over tank, I used to need to replace vacuum breakers often, about once a year. I say that the in tank softener was inadequate because it had limited capacity and gave no indication of when it needed to be recharged, hence it got recharged a lot less often than it probably needed.

Once I switched to full on cation softening, initially from Chris' cartridge systems and then later to a whole house softening system, vacuum breaker replacements became rare to non-existent.

I'm not really disagreeing with the thrust of Nicholas' idea, rather, I think there are different minerals and combinations of minerals that result from the various factors, e.g. the input water composition, and the sort of water treatment (other than RO or distillation) given to the water. The output water composition, regardless of its propensity to scale, is going to be different with a Claris system than from a cation exchange system. My own personal experience with cation softening, with the very hard water we have in my area, is that it does not seem to contribute to vacuum breaker dysfunction.

I don't know enough about the Claris system to comment on it, however I don't believe that it removes all the scale causing minerals, either. If I am mistaken, please correct me.

ken