I've been using a plumbed in Duetto III for about 1.5 years. The last couple of months it's developed an issue where both during heat up, and especially when turned off (i.e., cooling down), it leaks water into the drip tray. I understand this is normal during heating, but during cool down it's continuous and substantial enough to overflow the drip tray and continues to drip indefinitely.

I'm not particularly handy but don't feel like packing this up and shipping either. If it were just in heating I'd think the vacuum breaker or expansion valve needs replaced/adjusted, but the leaking on cool down has me confused. Any ideas would be very helpful.

Is the water dripping from the bottom of the cylinder below the grouphead? If so, it's the brew valve failing to seal properly. See Constant dripping from E61 grouphead for diagnosis and solution. If it's dripping from the expansion valve, then scale/grit may be preventing it from sealing properly.

There's plastic tubing behind the front plate that the drip is coming from. It's the same spot that would normally drip (a little bit) into the drip tray during heat up. I haven't tried anything yet but am planning on taking it apart tomorrow to poke around a bit.

I should have added that it has no issues with leaking when heated up... I normally leave it on for days at a time and it won't leak until I turn it off and cool the machine down.

ohwino wrote:...but during cool down it's continuous and substantial enough to overflow the drip tray and continues to drip indefinitely.

Overflowing the drip tray - YIKES ! That seems like a leaking fill solenoid valve for the steam boiler.

What is your line pressure? Do you have a pressure regulator? 2.0 to 2.5 bar seems like a nice range to me as measured (using the machine's gauge) with the machine shut off and the brew lever lifted.

There's no pressure regulator in the plumbing. I have the water turned off right now to stop the drip (my wife caught it overflowing on to the floor while I was out of town), but seem to remember it being on the high end of that, more like 2.5-3. It's not a fast drip by any means, but it's continuous for well after it's cooled down (at least 36 hours after being turned off based on this incident).

ohwino wrote:...my wife caught it overflowing on to the floor while I was out of town

I do not mean to make humor of this situation, but that is, in fact, a "good wife".

I am not familiar with the Alex plumbing but whatever silicone lines connect to the spout at the drip tray should be segregated such that you can confirm the source of the leak. A short trip to the hardware store for tube and barbed connections and you will be ready for the next adventure.

Finally had a chance to open this up and look around... looks like a more significant issue than I thought. Leaking (1) from some seal in the bottom of the brew boiler (which explains why it doesn't leak when heated/expanded), (2) somewhere in the back right of the machine onto the power cord, and (3) the drip out the silicone tubing.

Seems well beyond my ability to fix myself; I'm really disappointed in all this with machine not a whole lot more than a year old.

Then if you take some pics, I assure you that there exists some Alex Duetto experts (user name = DaveC) who can advise you on what can be done.

Certainly Chris' Coffee service is also intimately familiar with this machine but pics are important.

Thanks - here are a couple of images of the leak around the brew boiler and, while harder to see, a leak coming from somewhere in the back right that settles around the power cord (hard to make out the water pooling around the black cord but it's there). The latter doesn't seem to amount to more than maybe 10-20mL, while the former can be more significant. I don't think it's the water from the brew boiler that's overflowed the drip tray, however (I think that's coming from the silicone tube running out of the vacuum breaker valve), as I don't see how it would get into the tray from the brew boiler.

I'm going to go out on a limb here and take a stab that you only have one leak. However, the water you describe is in two different places, making me thing that it's dripping down from above, perhaps running along a line in the process. It would be very strange for your machine to develop two problems at the same time.

I agree you should contact CCS. Tim Catalfano (the tech there) is very, very knowledgeable about the Duetto and has helped me through more than one issue over the past few years. He has always hit the problem right on the head when I've described it to him - either on the phone (faster) or in email (you gotta wait fro him to get to yours). While I highly value DaveC's input and know only a miniscule of what he does about the Duetto (or any other espresso machine), his diagnoses have been hit and miss FOR ME. I'd say he's batting about .500 The tech support at espressoparts is also excellent. I had a tech on their online chat engine one day checking to see if I was ordering the right safety valve for my steam boiler and we got into a discussion about my machine problem...and he was able to teach me how to diagnose what was going on...and then I was able to fix it. I got the right safety valve in the process.

The other thing I would suggest is that you open the case while the machine is cold, and monitor the warm up process in order to see first hand exactly where your leak is. It'll go a lot further towards fixing it, than trying to deduce what's happening from where water is dripping and pooling, and any other symptoms.