I have a Quick Mill Silvano that has served me very well but I'm ready to upgrade to a machine with stronger, more consistent steam. A double boiler model in the category of the ECM Synchronika, Quick Mill Vetrano 2B, etc, seems most appealing to me but I have a question about the steam boiler in machines like these...

Most of them have steam boilers with about 2L capacity. I typically only pull 1-2 milk drinks per day. That's going to use up, what, maybe a tablespoon of water per day to generate that much steam? So I assume the vast majority of the water in the steam boiler would just sit in there for weeks or even months at a time being heated, cooled and heated again, until it finally cycles through at the rate of a tablespoon or so per day. Is that really OK, or are there health and/or taste downsides to such low usage in a small household with a DB machine?

The steam boiler on the synchronika can easily be drained through the hot water wand. So you can do that as often as you want if you're worried about the water quality.

I always take my cups off the top drip tray and pre-heat them on the drain pan grill with hot water from the steam boiler to make sure they're good and HOT and to help cycle the water through the steam boiler while flushing out most crud that might be building up.

On the La Spaziale Vivaldi machines heating the cups with hot water helps keep the water in the steam boiler fresh, and your cups warm. Most double boiler machines probably function the same way.

For any steam boiler, whether a single-boiler or double-boiler machine, draining the boiler through the steam wand every two weeks or so not only freshens the water but helps prevent scaling.

I respectfully think this to be false.

Draining water through the Steam Wand will likely make the situation worse as only pure water is released leaving behind any mineral content to further build up in the boiler. Draining water through the Hot Water Spigot, where the outlet is situated at or near the bottom of the boiler would be a much better choice than the Steam Spigot, whose outlet would be above the boiler high water line.

This applies to virtually all SB & DB machines.

IMO

My Spaz Vivaldi has a drain nut underneath, for draining the steam boiler. More effective than boiler draining through the hot water tap or (worse) the steam wand. (Note: If it's been a while, you may have to insert a screwdriver to break up accumulated scale and gunk before the boiler drains properly.)

Despite the fact that I drain the steam boiler very seldom (not even yearly), I have not run into any steam boiler issues. Not sure what health issues would arise from use of steam...

Thanks for the replies. It's good to know that there are a variety of workarounds. Having never owned a DB machine I didn't know if the water would end up stuck in there, which I see it won't.

With the Silvano all you have to do is pull 400 ml of water through the brew boiler and purge the steam wand for a few seconds, and you're using completely fresh water for your next round of drinks. I don't know how much difference that really makes but I like the idea of it so I've just made it part of my morning routine. Obviously if I go with the upgrade I described, that will have to change.

Draining water through the Steam Wand will likely make the situation worse as only pure water is released leaving behind any mineral content to further build up in the boiler.

I don't think he means depleting the water in the steam boiler by releasing steam, but by actually draining water out of it through the steam wand, or hot water tap.

I think draining the steam boiler is worthwhile as machine maintenance but correct me if I am wrong -- isn't any condensate that forms in the milk from steaming essentially distilled water? So I doubt you can have an adverse reaction to it.