thirdshifter wrote:Thanks for this explanation. I wonder though: is it possible that La Marzocco is right and we're overreacting to this issue? Isn't it likely that La Marzocco is aware of this problem and yet still thinks the benefits of the "finish your shot" functionality outweigh the increased wear on the pump? I guess this hinges on just how bad this is for the pump.

Personally I run low on water all the time. I mean, I try to avoid it but it happens at least weekly (I pull 8 shots/day off the reservoir and think I use a lot of water for rinsing). I know, I should plumb it in. But do you think I've screwed up my pump?-- is it going to fail next year? Or will it probably last as long as everybody else's with just a slightly increased chance of failure? Whaddya think?

I think if that's what LM said they are feeding you a line of crap. Last Shot protection - LSP (which I defined for the ACS-Vesuvius) needs to be a little cleverer than that). On the Vesuvius and the little ACS Minima (a much cheaper machine) it kicks in whilst there is enough water in the tank to complete the shot and some...no chance of sucking air. Also (and I suspect the LM doesn't do this), the ACS LSP won't allow a service boiler fill operation until the shot finishes...because that spoils your shot as well.

I am shocked LM can't get this right on such an expensive machine and I don't think there is any excuse, did no reviewers/testers bring it up? Or are people so dazzled by the brand that they think it's OK?

I don't know the specifics or nuances of this conversation, but just wanted to share my experience. While the LMLM can finish the shot even as the low water sensor comes on, in my experience, it does not completely finish the shot unless the low water sensor activates well into the shot (i.e. I can't keep the brew going until my desired time if the sensor kicks in too early, it'll shut off mid brew).

DaveC wrote:I think if that's what LM said they are feeding you a line of crap. Last Shot protection - LSP (which I defined for the ACS-Vesuvius) needs to be a little cleverer than that). On the Vesuvius and the little ACS Minima (a much cheaper machine) it kicks in whilst there is enough water in the tank to complete the shot and some...no chance of sucking air. Also (and I suspect the LM doesn't do this), the ACS LSP won't allow a service boiler fill operation until the shot finishes...because that spoils your shot as well.

I am shocked LM can't get this right on such an expensive machine and I don't think there is any excuse, did no reviewers/testers bring it up? Or are people so dazzled by the brand that they think it's OK?

I've to agree with this.

Sucking in the air can't be good for the pump and even destabilises the water circuitry as it might create pressurised air pockets.

thirdshifter wrote:
Personally I run low on water all the time. I mean, I try to avoid it but it happens at least weekly (I pull 8 shots/day off the reservoir and think I use a lot of water for rinsing). I know, I should plumb it in.?

8 shots a day using that reservoir, you have some patience, I do about 4 a day and I was always filling it up before I plumbed it. Plumb that baby if you can lol.

Hi,

tank you for all the answers and ideas.

RikC wrote:You could actually measure if your flow rate is higher than normal. Several reviews mention the flow rate the reviewers measured and there is also a lot of information to be found about it in topics that talk about changing the gliceur from 0.8 to 0.6mm (this reduces the flow rate).

Thank you for the idea, I will try that.

isabelo wrote:Is there a sink or some means to provide drainage for the machine in that area or wall?

Only with additional big holes to drill, so I will just use the drip tray and empty it manually.

DaveC wrote:Also (and I suspect the LM doesn't do this), the ACS LSP won't allow a service boiler fill operation until the shot finishes...because that spoils your shot as well.

LM actually does this on the Linea Mini, brewing has priority over filling the service boiler, you can event interrupt filling the boiler by starting a brew cycle.

DaveC wrote: I am shocked LM can't get this right on such an expensive machine and I don't think there is any excuse, did no reviewers/testers bring it up? Or are people so dazzled by the brand that they think it's OK?

I wrote an E-Mail to LM Germany, but they are completely unresponsive. I will try to give them a call soon, or write to LM US. My dealer told me they had talked to LM, and they acknowledged that it is normal behaviour. The dealer also was not aware of this issue before I complained, so either not every machine is affected, or most people do not notice it. I had to send in the machine three times (it got quite destroyed during shipping on the third attempt, but that's another story) and show them the movies I made until they actually understood the issue.

I personally think it was only tested with the reduced flow rate during actual brewing, but never during flushing the brew head (which is even a requirement according to the manual).

I suspect it works as follows: The sensor signals a low water level, the electronics starts a timer with a fixed amount of time, during which the water reservoir does not run empty when there is only the low flow rate of espresso brewing. Without the resistance of the puck, the flow rate is too high, and the reservoir does run empty. A firmware update decreasing the period of time the pump runs after sensing low water level could help, I assume.

I also fear that it might reduce the lifespan of the pump, as rotary vane pumps are not really made for sucking in air. Besides cavitation, if air gets trapped inside, especially with low water flow and high pressure, the friction might also increase leading to either a stuck pump or leaks.

I guess my next step will be to reach out to LM and get an official statement. I will report here once I have any news.

Crikey that is not a good look from LM for an expensive machine. Im sure we all feel your pain.

I've been using the Luminaire shot timer for three months and am quite pleased with it. I have it mounted on top of the back frame so it is unobtrusive but easy to see.

Anyone remove the fitting on the backside of the boiler going into solenoid (the gicleur is threaded into it). Mine developed a slight leak somehow, nothing major, but slow bubbling, not dripping. Found it because I have a slow pressure drop on the brew boiler gauge.

So, I have to take this thing out and am not sure how given that the threading is the same on each side of it. It is not like there is enough room in the machine to rotate the whole solenoid around.

Am I missing something?

Edit:

Yes, I was missing something. You have to take apart the 3 way valve in order to rotate the assembly around to loosen the fitting at the boiler. It was pretty gross considering I use clean water off a flojet. Either way, replaced it, put Loctite, pressure tested, and I'm back in business.

sluflyer06 wrote:It's easier than you think to drill for the dotshot, I did it and I'm not especially talented with drilling sheetmetal or anything. Lemme know if you want to know what I used and how.

https://photos.app.goo.gl/zthEhdPJYgTp2JvE6

Just curious, is that front facade of the LMLM easily replaceable? Kinda like how the top plate is just attached with 4 screws. Tempted to do this to my LMLM as well but i wanna know what my options are if i mess up lol

That piece wouldn't be as easily replaced as some others, but it can def be replaced if it needs to be. Id have to open. The top and look to see what would need to come apart