Been lurking on Home Barista for 6-7 years at least, figured I would finally join.

I have a La Marzocco GS3 that is about 3 years old and the past few weeks I have noticed a considerable amount of water (1-2 cups) in the drip tray every morning. It is set to turn on a 5am and shut off automatically at 10am if I don't turn it off manually. A few weeks prior, my wife kept hearing a strange faint rattle "coming from the ceiling". My old ears could barely hear it, but locating the source was elusive. Like a dripping faucet, it was driving her nuts, so I spent about an hour with a paper towel tube to my ear trying to locate it. Why it took me so long to connect the water in the drip tray with the new strange noise I can't tell you, but the noise is certainly coming from the GS3. Getting close it is almost a wet gurgle sound. Further inspection found water dripping every few minutes from the left-most drain hole when looking at the machine, the first of what looks like 3 drains grouped together on the right side of the drip tray. I am guessing this is the Over Pressure Valve that isn't sealing and the steam is condensing int he tube and filling the drip tray. Does this seem correct to anyone more knowledgeable than me? I will open it up this weekend to confirm, but wanted to see if there is any other location I should check as well?

It's almost certain that the water is coming from the vacuum breaker valve, which usually needs to be serviced every 6-12 months, but it wouldn't be surprising for the breaker to make it through 3 years without needing to be serviced.

See this post. It has links to photos and instructions. You can ignore the bit about the expansion valve.

It's conceivable that you have a defective OPV, but it's not very likely. It's not completely clear from the parts diagram which of the two left-most holes on the right side is the OPV and which is the vacuum breaker, and even if it was it wouldn't be surprising to find the tubes switched in some machines. It's no big deal. You'll be able to figure that out when you open the machine.

Most likely is time to chang all the o-rings. I had the same issue until I replaced all the o-rings.

Peppersass wrote:It's almost certain that the water is coming from the vacuum breaker valve,

That was it. Cleaned it up and working perfect. Thanks for the help.