I've had my Alex Duetto II for just over a year with no problems. Within the past month, I've noticed a strange smell that is definitely coming from the machine. It isn't a bad smell, more like a hot water/metallic smell, but very noticeable. I opened it up yesterday and did not see anything unusual - no visible leaks, corrosion, scale, melted insulation or plastic. I backflush with water after every session, and with JoeGlo about once a month. I just replaced the gasket and shower screen (after the smell started, so that is not the cause). The machine is plumbed in with a filter and pressure regulator; water here is soft. I also regularly take a few ounces from the hot water tap to get some fresh water into the steam boiler so it's not just sitting there. The machine is typically on for about 4 hours a day, I've got it on a timer so it is warmed up in the morning.

Any ideas what's going on? Anything to worry about?

If you don't have any leaks it might be caused by water spraying/dripping from your vacuum breaker unless it's plumbed into the drip tray. The valve might be spraying more water then before due to a gradual build up of deposits over the past year or it could be leaking slightly. Start the machine from cold with the body work off & see how much comes out. If it's excessive or the valve isn't fully sealing install a new one & clean the old one in white vinegar so you have a spare on hand.

There have been a few reports of the insulation on the boiler breaking down creating a weird smell when hot. I would follow the other suggestion here and take the top cover off. Turn machine on and try to track smell origin. If its that strong you should be able to identify source.

Warmed up the machine with the cover off. No leaks that I can see. The vacuum breaker is plumbed to the drip tray. The smell is definitely coming from the vicinity of the steam boiler. Probably the insulation.

Wow, I just found a year-old, very long thread on CG all about this problem. Seems like most people noticed it right away, not sure why mine seemed OK for a year. I'm calling Chris Coffee tomorrow. Sorry to bother everyone with an old problem.

What is the resolution for this? Have my Alex II for almost 2 years now and haven't noticed any weird smells <fingers crossed>

Some have reported that the smell will slowly go away. Others state they could not live with it- and stripped off they insulation. Some have reinsulated with many different offerings- ranging from dynomat, silicone matt and many others , with insulaton-fire resistance/proof being the key element. My Duetto will be 2 years old in June - zero issues since then with daily use. They use cheap ties to hold the insulation to the boiler- which will get brittle and fall off. I plan to replace them when they do. That could also account for the funny smell - plastic ties getting hot on the plumbing. Depends how OCD you are.

I called Chris Coffee. They expressed surprise that my machine started smelling after a year of use (rather than immediately), but they sent me replacement insulation. I removed the old insulation with only minor dissassembly and a bit of finessing, installed the new insulation - problem solved!

The foil lining of the old insulation looked a bit singed, and the outer foam was dry and crumbly. Definitely bad stuff.

My machine is on a timer and turns on at 6am to warm up; it stays on until 11am. About a month ago, I started having it warm up with both boilers on. I noticed the smell shortly thereafter. Prior to that, I only turned on the steam boiler as needed. So I'm guessing my new practice of leaving the steam boiler on for hours had something to do with the insulation failing. Once I noticed the smell, I was aware that it started as soon as the steam boiler got hot.

Even though there is no smell with the new insulation, I'm back to turning on the steam boiler only as needed. It saves energy and probably reduces thermal stress on the other components. And it heats up in minutes.

Sorry to revive an old post here, but an experience that I had may be worth while for users searching for reports of a simlar problem. Yes, the stock steam boiler insulation on many of the Duetto II units was degassing terribly, causing a room-filling smell and leaving a visible residue on anything sitting on the cup tray. But, after a year of use, this would not likely spontaneously develop (i.e., it would have been immediately noticeable and then decline over time).

However, I wanted to offer what I discovered on my machine (also a Duetto II) after smelling a suddenly new "hot" smell over the steam boiler after ~1 year of ownership. The tiny computer box wired to the PID display had fallen slightly off of the inside of the face of the machine and the corner of the box was resting on the boiler. There was a somewhat melted spot on the computer box marking where it was resting, and it seemed the smell was coming from that. After reattaching the box the smell disappeared. Occaisionnaly I notice the smell again, and find the box resting on the boiler when I remove the top cover of the machine.

Given the timeline of the problem you described, I suspect that this could have been the case on your machine, David, and that you may have incidentally moved the box off of the boiler when attaching the new insulation. Any return of the odor for you, David?