My machine has now reclogged; I had about 5 days of good flow and now it is back to around 300ml/minute.

I called LM USA yesterday and spoke with their tech, with whom I've had a couple of previous conversations. I told him that in all honesty I wish I had never bought this machine, that my Cimbalis had given me essentially zero problems over about 15 years of ownership, and that with less than 6 weeks of use I've already had to remove the solenoid 3 times, to open up the grouphead once, to put up with noise and vibration (worse than my vibe Cimbali) when the pump is engaged, and now after all this I'm back to square one with the same flow problems as before.

The tech was very empathetic and he told me that for some reason there had a been a number of people who bought the "fire sale" GS3s who have had similar problems with gicleurs, and that he could not explain it. In some cases the problems were clearly water quality related, people using hard water in their machines and depositing carbonate scale on the gicleur. In other cases there had been other explanations. He's been approaching this on a one to one basis trying to deal with each situation depending on what seems to have caused it. He did ask me to send him photos of the verdigris corrosion on the TL30, and I have done so.

In my case he has offered to make me a wider gicleur, 0.8mm across, which he'll have to fabricate for me because the stock one used on other machines will not fit the GS3s threads. He will get this out to me in a few days and I'll report back on how that is working out.

ken

Ken Fox wrote:My machine has now reclogged; I had about 5 days of good flow and now it is back to around 300ml/minute.

Oh, Ken, I am so sorry to hear that. I'm sure you're feeling exactly as I felt after numerous drainings, disassemblies and reassemblies of my first GS/3, sometimes restoring good flow, only to have the cursed problem return after a few days. Now you can understand why, after weeks of futile repair attempts and many hours of wasted time, I insisted on a replacement machine. My worry was that the dealer would "repair" the problem, but it would come back a few days after the machine returned. I foresaw hundreds of dollars in back-and-forth shipping charges and days/weeks without a machine. Your experience has justified that fear.

To be fair, I didn't know about the swarf problem back then. If I had, and had I realized how relatively easy disassembling the group is (compared to a lot of other stuff I had done in the course of attempting repair), I probably would have gone down the same road you did. And I probably would have ended up asking for a replacement anyway. I'm going to go out on a limb here, but I think cleaning or even enlarging the gicleur will only relieve the symptoms temporarily, and will not cure the problem.

I believe that nothing is going to solve this problem short of removing the boiler and cleaning out all the swarf (if that's even possible) or replacing the boiler. I also think it would be prudent to replace TL30, for reasons explained below.

I think swarf is sitting on the bottom of the boiler and/or is adhering to the sides, and periodically some of it gets carried up into the group head by the water flow. Once there, it inevitably finds its way to the gicleur, where it adheres to the stainless area around the ruby insert. When you pull a shot, particles of swarf get swept against the gicleur, where they partially block the flow. My sense is that pieces may not be getting sucked all the way into the hole, but are either loosely adhering to the stainless material around the ruby or are partially lodged in the hole, with a portion of a piece in the hole and a portion remaining outside. I believe this because the simple act of draining my brew boiler would sometimes restore the flow rate. In this case, I think the draining water pulled swarf away from or out of the hole and back into the group head, and maybe even back into the boiler. I don't think any of this dislodged swarf made it out of the OPV, however. At least, I never saw any. It's conceivable that smaller swarf actually gets stuck deeper inside the gicleur, but I think if that was happening it's less likely that draining the boiler would have pulled it out. But it's a possibility.

I think some pieces of swarf are large enough that even a .8mm gicleur will be vulnerable to clogging. I think so because I found larger pieces of swarf inside the dispersion block screw. Besides, if there are small pieces of swarf in the boiler, could there be really tiny pieces that can get through the dispersion screen and into your cup?

My sense is that the first order of business is to make sure there's no loose material left in the boiler. Obviously, taking out the brew boiler would be a major operation (I think if I did that I'd take out the pump and motor, too, and permanently relocate them outside the machine.) Once out, I'm not sure what would be required to ensure that not a speck of swarf remains in the boiler. The holes leading into the boiler are quite small, so it would be tough to get a brush in there, and tougher to inspect the interior (which may be why the swarf is in there in the first place.) I think a fiber-optic scope might be required (don't laugh -- an HB member who visited me is a doctor and is planning on using one to check for scaling in the steam boiler!)

Given the uncertainly of the effort, I would say the better course of action is to replace the brew boiler with one that LM has thoroughly inspected for swarf. It seems only reasonable to replace TL30 at the same time, mainly to replace the gicleur in case there are tiny bits of swarf inside. It's possible swarf could be inside the copper tubes, too, so as long as the brew boiler has to be replaced, why not replace TL30 at the same time?

My guess is that this would fix the problem. That said, my natural paranoia has conceived of one further failure mode: swarf from the boiler may have gotten out through the inlets to the check valves and could foul them. When removing the brew boiler, I think it would be wise to clean as many of the check valves in the path as possible, and flush out all the copper tubes.

Now, it makes sense to me that this repair is so involved that it warrants replacement of the machine by the dealer/LM (perhaps with a machine that has been thoroughly bench tested for several weeks.) They can then repair your machine as suggested above, test it for several weeks, and sell it as refurbished. That said, you may prefer to keep the repaired machine (or repair it yourself) to avoid the possibility that the replacement machine has a swarf problem, too.

But I'm going to take the position that cleaning or replacement of the brew boiler is mandatory.

Peppersass wrote:Oh, Ken, I am so sorry to hear that.

I believe that nothing is going to solve this problem short of removing the boiler and cleaning out all the swarf (if that's even possible) or replacing the boiler. I also think it would be prudent to replace TL30, for reasons explained below.

But I'm going to take the position that cleaning or replacement of the brew boiler is mandatory.

Actually, my own sense of this is different. I believe that what is clogging the gicleur now is the corrosion/verdigris on the copper TL30 coming off in minute pieces and causing the clog. At some point the copper portion of TL30 is going to be completely coated with this verdigris and at that point I think it will become much less likely to dislodge material. I think this explains why a percentage of owners of this equipment have experienced this problem, and that the problems have occurred after a few weeks of ownership. I also think that when I took the head apart last weekend, that although I cleared the gicleur clog, my manipulation and attempted cleaning of the verdigris on the TL30 probably inadvertently contributed to the later dislodgement of the verdigris, clogging it now. One way to be more certain of this would be to carefully examine the ruby gicleur before doing anything else to it, when I disassemble the group head again shortly after receiving the new part(s) from LM next week. If there is no evidence of metallic fragments around the gicleur orifice, and instead I see material that looks like the verdigris, then I think I'll have my answer.

If you have already really flushed out the group head, as I have done, then you need to come up with a mechanism for this stuff to get back up into the group head. If it was minute metallic pieces (which is what the swarf principally would be) clogging up the gicleur, then you would have to posit that these pieces can float, and hence migrate up from the bottom of the boiler up into the head; the boiler does not fill directly into the head, and I don't think that it fills from the very bottom, either. Granted, the brew boiler fills with line pressure, which in my case is regulated at 3.5 bar. I doubt that 3.5 bar is sufficient to cause metallic fragments to be pushed up into the group head, when logically they would be expected to come to rest at the bottom of the boiler around the heating element. Also, you would have to posit that the boiler and the plumbing is chock full of swarf, and I sincerely doubt that to be the case. Since the gicleur sucks in water from a dependent part of the group head, in its "neck," it is much more likely that the responsible material was swirling around in the same place, which makes the verdigris much more likely in the case of a group head known to be spotless a few days ago.

My working hypothesis is that there is more than one cause for this problem in GS3s, and it has apparently happened in a number of them. The orifice in the gicleur is very tiny, just 0.6 mm, which is the central issue, so just about anything can clog it, be it scale, swarf, or the verdigris that I observed. This is a design issue (or "feature," if you will ). I think it is probable that some machines have a little bit of swarf in the group head that can get directly sucked up as the machine is used, and maybe in the process of being shipped other machines have swarf from elsewhere in the boiler that ends up in the group head. Once that swarf is removed by whatever means, I really doubt that there is a pool of swarf elsewhere in the machine that keeps migrating up into the group head. I also don't think that LM has such a sloppy manufacturing process that more than a tiny bit of swarf is present in any machine; it is hard to imagine that LM would ever have become a well regarded manufacturer if that were the case.

I guess it is possible that the new 0.8mm gicleur I am to receive will also clog up. That should become apparent over a few more weeks to a month. If that happens then we either need to go to an even larger gicleur, or we need to rethink about the best way to approach this.

This problem does not strike me as being equivalent to buying a car and getting stuck with a "lemon." My machine is otherwise fine, except for the vibration issue, which will be fixed with a longer braided hose shortly. The gicleur clogging is a simple and straightforward plumbing issue. My best guess is that if the machine were replaced there is certainty that whatever is present in my water that has caused the copper TL30 to corrode is still present. If there is a reason for any of it to dislodge during the early part of my ownership, a clog would result in the new machine. If instead the gicleur did not clog early on, it would probably not clog later because the verdigris would form a stable structure on the copper tubing and would stay there.

As to the idea of ingesting "swarf" in one's espresso, I think that is far fetched. The swarf would have to make it all the way through the puck and the group screen before entering your cup. There are lots of things in this life that I worry about, but that one would be down near the bottom of the list . . . .

ken

Ken Fox wrote:I guess it is possible that the new 0.8mm gicleur I am to receive will also clog up. That should become apparent over a few more weeks to a month. If that happens then we either need to go to an even larger gicleur, or we need to rethink about the best way to approach this.

Very sorry to hear that you're having such annoying difficulties.

FWIW, the 0.6mm gicleur in my Speedster started to scale up within a few weeks. (It's stainless steel, no ruby). I replaced it with a home-drilled 0.7mm, which seems to scale up a lot slower.

As you know, Paul Pratt came up with a solution to the problem here. It doesn't eliminate the scaling or clogging, it just would make it simple to maintain the flow when restriction occurs.

AndyS wrote:FWIW, the 0.6mm gicleur in my Speedster started to scale up within a few weeks.

Andy, out of curiosity, did that occur even with the gargantuan water softener installed?

gyro wrote:Andy, out of curiosity, did that occur even with the gargantuan water softener installed?

No softening, just a charcoal filter.

Ken Fox wrote:Actually, my own sense of this is different. I believe that what is clogging the gicleur now is the corrosion/verdigris on the copper TL30 coming off in minute pieces and causing the clog.

Possibly. It's not clear from your photos how cohesive or powdery the green stuff is, and whether it would tend to accumulate around a small orifice. It'll be interesting to see if you're right.

Ken Fox wrote:If you have already really flushed out the group head, as I have done, then you need to come up with a mechanism for this stuff to get back up into the group head. If it was minute metallic pieces (which is what the swarf principally would be) clogging up the gicleur, then you would have to posit that these pieces can float, and hence migrate up from the bottom of the boiler up into the head; the boiler does not fill directly into the head, and I don't think that it fills from the very bottom, either. Granted, the brew boiler fills with line pressure, which in my case is regulated at 3.5 bar. I doubt that 3.5 bar is sufficient to cause metallic fragments to be pushed up into the group head, when logically they would be expected to come to rest at the bottom of the boiler around the heating element. Also, you would have to posit that the boiler and the plumbing is chock full of swarf, and I sincerely doubt that to be the case. Since the gicleur sucks in water from a dependent part of the group head, in its "neck," it is much more likely that the responsible material was swirling around in the same place, which makes the verdigris much more likely in the case of a group head known to be spotless a few days ago.

Without going so far as to say it isn't verdigris this time, I don't agree with your analysis of swarf in the boiler. First of all, when you pull a shot, water moves into and through the boiler at circa 9 BAR pressure, not line pressure. Second, the temperature of the water coming in is lower than the temperature of the water in the boiler (although the input water is preheated by heat exchange in the steam boiler.) That temperature differential, along with the water pressure, is bound to cause turbulance in the boiler. I think these currents could sweep swarf off the bottom of the boiler, or off the sides, and carry it into the group head. The swarf particles I saw in the dispersion block screw were very thin and lightweight.

Ken Fox wrote:My working hypothesis is that there is more than one cause for this problem in GS3s, and it has apparently happened in a number of them. The orifice in the gicleur is very tiny, just 0.6 mm, which is the central issue, so just about anything can clog it, be it scale, swarf, or the verdigris that I observed.

I do agree that there could be multiple causes, and I agree that the gicleur is the Achilles Heel of the GS/3. (If only it was more accessible!) But I find it odd that you found swarf on the gicleur, which must have been the cause of the original flow rate problem, and now you have something entirely different clogging up the gicleur, supposedly the result of your attempt to clean off the verdigris. Seems like too much of a coincidence to me. But your examination of the gicleur will settle the matter.

Peppersass wrote:I do agree that there could be multiple causes, and I agree that the gicleur is the Achilles Heel of the GS/3. (If only it was more accessible!) But I find it odd that you found swarf on the gicleur, which must have been the cause of the original flow rate problem, and now you have something entirely different clogging up the gicleur, supposedly the result of your attempt to clean off the verdigris. Seems like too much of a coincidence to me. But your examination of the gicleur will settle the matter.

Something I did not mention because I did not think of it when I made the original posts:

If you look at the gicleur, what you see is a metal tube that encloses a synthetic ruby with a hole drilled into it:



Before I looked at the front part with a magnifying loupe (the constricting part, all I could see since I did not unscrew the gicleur from its attachment on the TL30 part), I made vigorous attempts at clearing out the passage in the gicleur with a thing guitar string wire. I had pushed the wire through the gicleur and then manipulated the wire at both ends in all possible directions.

It is possible that some or all of the metallic fragments I saw surrounding the entry point of the ruby gicleur could have been shavings that I produced from the metal tube surrounding the gicleur at its front, the lip surrounding the front of the gicleur.

If this is the case then I did not actually see the "swarf" that we all have been discussing, rather I saw metal fragments that I shaved off with the wire. In that circumstance the actual cause of the clogg, which I relieved with the guitar string, remains unknown, although just as real.

In any event, I do not believe that any, or certainly very many, of these effected machines have some significant quantity of metal fragments left over from manufacturing that are swirling around in the GS3's plumbing, awaiting an opportunity to clog the gicleur. Having an entry orifice that is that tiny, 0.6mm, does not require much more in the way of an explanation for why these things are clogging up in some of these machines.

ken

Peppersass wrote:Without going so far as to say it isn't verdigris this time, I don't agree with your analysis of swarf in the boiler. First of all, when you pull a shot, water moves into and through the boiler at circa 9 BAR pressure, not line pressure. Second, the temperature of the water coming in is lower than the temperature of the water in the boiler (although the input water is preheated by heat exchange in the steam boiler.) That temperature differential, along with the water pressure, is bound to cause turbulance in the boiler. I think these currents could sweep swarf off the bottom of the boiler, or off the sides, and carry it into the group head. The swarf particles I saw in the dispersion block screw were very thin and lightweight..

Pressure has nothing to do with it, it's water velocity and I'm guessing that's quite low in the boiler, in fact, it's likely close to not there. The brew boiler is full so an ounce or 2 of water travels through it during the 25 second shot, much more while flushing, but the tube going in is 6mm or so ID and the tube going out is .6mm so the stream of water flowing into the boiler in something useful like inches/second is probably close enough to 0 to consider that it causes no disturbance that would be significant enough to move a piece of metal close to or bigger than .6mm in any dimension.

Now maybe I completely misunderstand the water path through the machine, but I all the flow paths I've seen have been quite similar in that way.

Ira

If the copper tubing in the head is causing a particle problem, could some type of sacrificial material be added to the tubing to reduce the problem? I am thinking something like we see on boiler elements.

-Cecil