La Marzocco GS3 moody solenoid

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by PhillySteve »

My GS3, with a good 14 years on her, has begun to stop outputting brew water after heating up for a while. It is odd, because as soon as it comes up to temp (brew and steam boilers), the espresso pours just fine. I get that "CLICK" at the solenoid and water emerges. But if I wait to long after turning it on, even 15 min too long, the brew water does not some out. I press the brew button, but no "CLICK" and no water. Just a frustrated pump running against a closed valve.

Any ideas?

Right now I have the 3-way and brew solenoids soaking, awaiting reassembly. But I fear it may be more "electrical" in nature. We'll see.

PhillySteve (original poster)

#2: Post by PhillySteve (original poster) »

The solenoids were cleaned and replaced. They operate very smoothly. But the issue persists. I'm left to wonder if the coil on the brew-water solenoid is bad (fails to work once hot) or if the control circuitry is the culprit. The only thing that is clear, is that the machine works flawlessly immediately after heat-up, but stops working about 15 minutes post heat-up. I guess the cheapest option would be to try replacing just the coil.

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BaristaBoy E61

#3: Post by BaristaBoy E61 »

PhillySteve wrote:Any ideas?
You might try disconnecting the wires on the solenoid, connecting a DDM to the solenoid leads, measure the continuity that should be in the lower ohms range (less than 1k ohms). Wait for the machine to get up to temperature, activate a mode that would send power to the solenoid and measure voltage at the disconnected solenoid power leads after measuring continuity at the solenoid that is now up to temperature for a ∆Ω.

Only doing this if you are confident of your skills working on a live machine!
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

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Team HB

#4: Post by Jake_G »

You could also use the DMM to see if the machine is successfully calling for the solenoid to open...
LMWDP #704