My GS/3 has been intermittently leaking extremely hot water / steam out of one of the OPV's feeding into the drip tray. Looking at the manual I wasn't able to figure which valve the leak is coming from, but the picture below shows the top right side of the drip tray where the 3 metal pieces protrude down from the body of the machine. The drip is coming from the left one of those three -- anyone know which OPV that is? Is replacing it fairly straightforward?



Looks like I'm going to need to replace the drip tray eventually too, since the dripping has melted part of the plastic. Anyone know the best place to order one of these?

Thanks,

Frank

According the La Marzocco GS3 Operating Manual pg.7 par.8 indicates this is the expansion valve. On my machine it drips a little which is quite normal. Your expansion valve looks like its been adjusted due to the wear marks and abrasions.

Hi Marlon,

I believe the expansion valve is the one on the far right, isn't it? I know that's the one I adjust to set the maximum brew pressure it vents out. The one on the left is the one that's leaking, and I don't know if that one can be adjusted or not (never tried).

Thanks,

Frank

The two fittings on the left are drains for the steam boiler vacuum breaker valve and the steam boiler OPV. They're just hose barb fittings, not adjustable valves. The device on the far right is the coffee boiler OPV. As you pointed out, it's adjustable.

My GS/3 was made before they added the vacuum breaker drain, so I can't tell you which of the two fittings on the left goes to the OPV and which goes to the vacuum breaker valve. It's hard to tell from the explosion diagrams in the parts catalog.

So, unless someone else can tell you which is which, take the right side panel off the machine and trace the clear plastic tube that's connected to the fitting on the far left. It will lead either to the vacuum breaker valve on the top right of the steam boiler or it will lead to the can that houses the steam boiler OPV, located between the two boilers, roughly in the center of the machine. The clear plastic tube connected to the center fitting will lead to the other valve.

Most likely it's the vacuum breaker on the steam boiler that's leaking. That's pretty normal after a few months of service, depending on your water composition. If it's leaking, you need to service the valve. You'll find all you need to know about that in this thread.

Thanks Dick, I'll open up the hood and take a look (and report back).

Frank

Peppersass wrote: Most likely it's the vacuum breaker on the steam boiler that's leaking. That's pretty normal after a few months of service, depending on your water composition. If it's leaking, you need to service the valve. You'll find all you need to know about that in this thread.

Dick is correct:
Its the Vacuum breaker. I had this issue just a few months ago. You can buy a new o-Ring or replace the entire breaker from LM for like $35. I opted for the o-ring but I can't for the life of me remember the size.

-Justin