La Marzocco GS3 flooded my kitchen

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
erik996
Posts: 102
Joined: 15 years ago

#1: Post by erik996 »

Setup: 2016 GS3 AV, plumbed using oem parts. Programmed to turn on at 4am, turn off at 3pm. Been working fine. It drips a reasonably annoying amount of water from the right side of the group under the control panel (see picture below), but it goes into the drip tray, so I empty it every few days. I can live with that.



This evening, I got home and it was off, as it was supposed to be. I turned it on (function + power button on the front of the machine) and it seemed fine. I tested out a new puck screen I got, then turned the machine off (function + power button) and left to run a couple errands. I get home and there are a few gallons worth of water on my kitchen floor. Machine was off, and water was streaming out of the brew solenoid drain tube (see picture below). Only way to stop it was to shut the water line off.



I cleaned up the mess, and verified this was where the water was coming from. I turned the machine on again, pressed the function button a couple times to make sure the solenoid was working, then opened the water line so water flowed, and it was just fine. No more leaking from the brew solenoid drain valve.

What the heck happened???? Did the solenoid get stuck open? Is there a wrong way to turn the machine off?

PS: is the other drain/drip normal? It's part of the "hydraulic assembly" in the parts manual and may be related to the hot water tap. In another machine, I had a leaky hot water tap due to scale buildup in the solenoid valve, so not sure if that's it with this or not.

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BaristaBoy E61
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Joined: 9 years ago

#2: Post by BaristaBoy E61 »

Do you know what your water line pressure is measured in psi or bar?
Do you have a water line regulator with a gauge?

You would also benefit from a leak detector with automatic water line cut off.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

erik996 (original poster)
Posts: 102
Joined: 15 years ago

#3: Post by erik996 (original poster) »

BaristaBoy E61 wrote:Do you know what your water line pressure is measured in psi or bar?
Do you have a water line regulator with a gauge?
You would also benefit from a leak detector with automatic water line cut off.
I've never measured my house water pressure. That being said, the water coming from my faucets has never "seemed" high. I have a water pressure gauge ordered, and an in-line pressure regulator is also on the way.

Seems, for whatever reason, the solenoid at the group was not fully closed. Hasn't happened before or since. I'm less concerned about the water pressure than figuring out why the solenoid was open, but I'll take care of any water pressure issues to get that out of the way.

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BaristaBoy E61
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#4: Post by BaristaBoy E61 »

erik996 wrote:Seems, for whatever reason, the solenoid at the group was not fully closed.
What's your water quality like? Are you using non-scaling water?
Scale can interfere with solenoid function.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

erik996 (original poster)
Posts: 102
Joined: 15 years ago

#5: Post by erik996 (original poster) replying to BaristaBoy E61 »

The published report from my water utility indicates very low dissolved solids. I removed the boiler from my old E61 HX to get it descaled after a decade of being plumbed directly to the water (mostly as a precaution), and there was no appreciable buildup except for about a 1/16" ring at the upper water level area.

I bought the machine used, so I can't speak to it's history, however it's from the same area running similar water.

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bostonbuzz
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#6: Post by bostonbuzz »

I think you got lucky and caught a failing seal before it did more flood damage.

If its under mains pressure then the brew boiler is under that pressure 24/7. If you have a brew solenoid issue then you will have the described symptoms. The solenoids have a plunger that is $30 to replace and holds water back by a mechanical spring (solenoid is doing no electrical work). It is either ruby or viton based on the machine age and will wear out or get coffee particles stuck in it from time to time. If your machine is 8 years old it might be time to replace them all.

After you brew, the water in the brew circuit that is in the HX in the steam boiler will superheat and increase the pressure. You will see your gauge go up to around 12 bar and slowly go down over the next hours. This indicates proper function of the solenoids and one-way valves in the brew circuit. With the machine off and fully cooled down you can see your house water pressure by just looking at the brew pressure gauge.

The OPV is a very simple spring and rubber washer brass item that you can rebuild or replace in accordance with the manual instructions. It keeps the brew circuit under 12bar in normal operation and shouldn't be leaking below that pressure if you haven't been brewing recently.

I rebuilt my 2010 machine over the summer La Marzocco GS3 AV --> EP Paddle Mod and replaced one of the viton sealing plungers in the solenoids (steam boiler fill). That solenoid doesn't see hot water, so your brew solenoid starting to fail after 8 years is not surprising. My ruby brew solenoid one is just fine but LM switched away from that for some reason in new machines.
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