Reading what you linked to, it says, “At temperatures above 212°F (100°C), the steam percentage you set specifies the amount of steam the oven will generate. In this mode, steam generation is constant and steady throughout the cooking process.” That’s not what I’m observing, though I will try again and watch closely.
Below 212°F, yes. The glass gets condensation, and water vapor eventually starts to escape below the water tank. Above 212 it just seems dry. Maybe a little condensation by the bottom of the glass at the end, but that could have been from the food.
Right now, I’ve just been experimenting with the oven. I’ve owned it since late November, but I’ve had it replaced once already, as the first one arrived with a manufacturing defect (loose screw). I hope this one doesn’t have a problem too. But I do get all the signs of water usage below 212°F. So it doesn’t seem like a physical defect, just a logical one (but I’ve not ruled out the logical defect isn’t in my wetware ).
Mostly I’ve been reheating pizza, to get an idea how things work, but just ending up confused on this. I wanted to dial in my own recipe, because the one in the app left the pizza too dry, and way too hot. I was trying to get a lower finishing temperature and more starting steam. The app recipe does 100% steam at 450°F for 5 minutes, then stops the steam at the same temp for another 5 minutes. It never reaches 450 during in the first 5 minutes, but gets close by the end. If I do 212°F 100% steam, and tell it to hold for 1 minute after reaching that temp and head for 350°F with no steam for 5 minutes, I get a nice finishing surface temperature and crispness, but a little soggy in the middle. My thought was try to bump up the temperature for 100% steam phase to allow the water to escape the pizza quicker during the crisp phase. But, that also makes a dry pizza, like its doing something completely different, and thus prompted this post.
I’ll try running a simple 100% steam, 250°F, empty oven and observe closely what happens. Do you notice, right after starting with those settings, a click coming from the area in the back of the tank? Then a few seconds later a second similar click? I get that at and below 212. In my mind it sounds like it’s opening a valve to let water into the oven, and then closing it. Above 212°F, I don’t hear that at all. How long did you run your 250°F test? Maybe it doesn’t add water until temperature is reached?