La Marzocco Linea Mini Leaking After Plumb In

Need help with equipment usage or want to share your latest discovery?
Jrodanapolis
Posts: 146
Joined: 4 years ago

#1: Post by Jrodanapolis »

Hi All,

I posted in the Linea Mini user thread about a minor issue I was having, but upon plumbing in it's become more severe.

While using the reservoir, I was having to refill after every 3-4 shots, which didn't seem normal to me. I'm using what I think is a lightly used 2020 LMLM. I swapped the plunger in the brew solenoid but I'm not sure that helped at all - still had to refill the reservoir after about 4 pulls (maybe one steam of enough milk for 2x capps, too). My static pressure also drops to zero when not brewing rather than 12 bars.

Here's a video of the drainage issue after installing a new plunger:
While swapping the plunger, I noticed that the discharge tube had been sheared off previously:


I dont believe that this would cause drainage issues, but isn't ideal of course. I've asked LM if they can help replace that discharge tube because supposedly there was a bad batch of them produced but haven't heard a reply yet.

I tried plumbing my machine in for the first time last night using a flojet and a BWT filter with the pressure reducer (flojet is temporary while I get a water line run) and am running into an issue. If the pressure is over about 3 bars, the water just constantly runs and pushes through the discharge tube. It just keeps flowing and doesn't stop. If I turn the pressure down to the point where that flow stops, I think I get a vacuum between the pump and filter..? The flojet pump stops running entirely, and doesn't kick on if I activate the brew paddle, so the LM pump starts cavitating. The reason I think a vacuum is forming is because the PEX tube is extremely hard to remove from the filter (vacuum holding it on) and if I open the drain tube on the BWT filter, it sucks air into the system.

I'm not using an accumulator (didn't think I needed to for very light use) and I'm not using a check valve near the flojet. Do I have to use a check valve here for some reason if I'm not using an accumulator? Or do I have an issue with my machine that was causing my previous water problem and is causing the current water problem? When I've used this flojet with a 2 or 3 group in the past, it works flawlessly with no continuously flow or vacuum created.

Thank you all in advance!

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Jake_G
Team HB
Posts: 4238
Joined: 6 years ago

#2: Post by Jake_G »

Hey Jordan,

You need to replace your entire brew solenoid. That's the only thing that can cause a leak from the brew group to the discharge tube. It is possible there is crud in there and you can remove the plunger and inspect/clear out the crud, but just save yourself the headache and get a complete solenoid body with a new plunger and be done with it.

Cheers!

- Jake
LMWDP #704

Jrodanapolis (original poster)
Posts: 146
Joined: 4 years ago

#3: Post by Jrodanapolis (original poster) »

Thanks Jake! I called a local repair shop and they said the same thing. I originally thought the same thing too, but when I asked the seller what they thought they didn't think that should be the case.

Hoping that solves the issue and I can put this one behind me. Will update the post when I get the replacement so that anyone else having a problem may be helped too.

Ahmad H.
Posts: 132
Joined: 3 years ago

#4: Post by Ahmad H. »

That solenoid and discharge tube doesn't look anything like the original La Marzocco parts. That's weird...

I recommend to change the solenoid as mentioned by Jake.

Jrodanapolis (original poster)
Posts: 146
Joined: 4 years ago

#5: Post by Jrodanapolis (original poster) »

Well, this became a much more drawn out issue than I was hoping it would be, but I'm glad to say I'm back up and running with a much-improved machine.

LM honored my warranty, even though it was about a month past two years when I brought the problem to their attention. They sent a replacement solenoid, but they sent me a 230 V version (how LM Home USA sends a 230 V solenoid is beyond me...), so I had to wait another week for the 120 V to arrive. I got that installed, and my leak went away! Woohoo!

At this point, I was stoked to give the pre-infusion a try. My 2016 LMLM doesn't have the retrofit kit, so I've just been running at a flat 9 bars and have been patiently waiting to see what the line-level feature was like. I turned the machine on, let it warm up for longer than I was planning to, and came back to no red light on. Checked what could be the issue, and the tstat was popped. But it wasn't just popped out, it had launched the entire red button out of the body! It was nowhere to be found, and I later took the back panel off to find it laying in the bottom. Ugh. So, bought a new one of those, installed it, and ready to give her a go yet again.

Turned the machine on, waited until the red light went solid, and gave the group a flush to be greeted with almost entirely steam. Contacted LM Home and they were able to check the temp on my brew boiler - 140 C. No wonder the tstat had decided to call it a day. Called Chris, LM Home service manager, and asked him to check on previous warranty work that this machine had. Sure enough, a service was performed on this machine about a year before I got it (machine was ~6 months old), but I wasn't told what was done. Finally convinced LM to send a tech over to assist, and they arrived yesterday with a new board, potentiometer, (another) tstat, and discharge tube. After we got everything replaced, the machine appears to be functioning perfectly.

The tech and I came up with the following theory:
Previous tech, for some unknown reason, replaced the brew solenoid with a non-ODE solenoid thinking it would function the same. That was causing leaks with the reservoir, and full blown, non-stop water to run through it when plumbed. When putting the machine back together, the unknown tech from a year ago sheared off the discharge tube flare and used a rubber gasket to attempt to collect the water from the top of the solenoid. Water was leaking from this faulty connection, and somehow making its way to the brew boiler tstat. Some sort of short occurred at the tstat, frying a part of the board. Machine still functioned, but the temp control feature of the brew boiler didn't anymore, causing the tstat to pop.

I just ordered a long braided line and put together a 3 wire cable with bullet terminals to outboard the motor. I'm still using the 2016, but hoping I'll have some time this weekend to outboard the pump and finally give the pre-infusion feature a try.

I'm frustrated with the number of issues the machine has had, but am thankful for LM's assistance in getting the right parts to me.

That being said, does anyone have an idea about what component on the board could have been fried? I wouldn't mind getting it repaired to get my 2016 IoT'ed.

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Jake_G
Team HB
Posts: 4238
Joined: 6 years ago

#6: Post by Jake_G »

If you post some pics of your board, we can theorize what might need to be replaced.

I'm curious how LM checked the boiler temperature if your machine is not IOT'd?

I know we had talked about getting PI up and running, but once/if you get the IOT upgrade, you can just use PI without any mods at all!

Cheers!

- Jake
LMWDP #704