Evening all. I've come across a Rancilio S27 that was left for dead at a local restaurant that has now shut its doors. I've begun disassembling the unit and have now reached the point of descaling the boiler. Problem I've come across, is the boiler won't seem to clean up. I've already used a pretty heavy dose of citric acid and boiling water, flushing and refilling over and over.

The inside has traces of copper coming through but it looks as if it's chrome plated on the inside as well? I scratched up the inside with some sandpaper to see how deep the "black" patina is and all I could get to was shiny silver.



I've snooped around here and have only come across the usage of muriatic acid which I'm leery of using. Simply for the fact that I don't want to do damage to the boiler, and that I might not get all of the acid out of the boiler afterwards, then transferring it to my drink.

I'm sure there are some Rancilio S27 users on here that could weigh in?

I just started restoring a 21-yo Rancilio L6, which I believe has a nearly identical boiler. That's about how mine looked after cleaning. I think the nickel plating (I'm assuming it's nickel, could be chrome) just wears off over time and you end up with bare brass in most of the boiler. Though, I'm new to espresso machines so I could be completely wrong. I figure once the scale build-up was gone, it was 'clean'.

Well I'm glad I held off on the muriatic acid. A bit extreme I think, especially if this boiler is nickel plated brass or copper. I'm just used to seeing this,



when all's said and done. The Rancilio boiler still looks dark and dirty even after repeated citric acid soakings.

What you're used to seeing is copper replating from the descaling solution. That "pink" will polish right off. FWIW, muriatic acid is just hydrochloric acid. I have used it for what I call "express descaling", where I needed to get it done fast. It is tricky to use and requires care and vigilance. Don't use it with stainless steel parts.

The first shot of the cleaned boiler certainly looks clean enough to me.

Thanks for the input Barry. Nice to get some feedback from someone else who has experience. I've given it one more citric acid bath and now it's on to the frame restoration and cleanup.

One thing that is bugging me is the teeny tiny HX tube that's attached to the boiler lid. I'd like to take that off but had already had dealings with espressoparts and their supposed "jedi", who bluntly stated the tube is discontinued, only after he requested a part number from ME. Thought that was supposed to be the other way around, but I digress.

A local Panera still has a s27 in usage so I find it a bit hard to believe that parts are now discontinued for it? In any case, thank you for weighing in!

Is this really a S27? The parts you are showing look entirely different than the one I rebuilt.

Maybe there was a different version?

I think the second picture is his other machine. The first one is the S27, which looks a lot like my L6 boiler.