The S1 Cafe - Helping Your Espresso Dreams Become Reality

So I plan on doing a little preventative descaling of my Mini steam boiler using a citric acid solution.

Any suggestions on which fitting to take off? I'm thinking the vacuum breaker might be the easiest one to remove. Does it just use a wrench? Do you wrap it with teflon tape afterward?

The guys at Chris Coffee say they fill it with citric acid then flip the machine on it's back and let the acid drip out the steam wand. Hmmmm....can't see how that works.

Seems like to tip the machine on its back and drain, it would require removing the steam fitting or better yet the hot water fitting on the back of the top of the boiler to work (see photo on the link below). Not sure I want to unscrew those fittings. Look pretty solid to me. I assume you would need to remove another fitting as a vent as well (or maybe just leave the steam lever open).

On this other site they say to use a syringe. That seems more likely to work.

http://coffeetime.wikidot.com/s1-mini-vivaldi-descaling

I like the idea of welding on a drain boss, but the price they are asking is more than a new boiler.

Who did you talk to about adding the drain? A welding shop? Is your boiler brass or stainless? Should be pretty straight forward. Drill hole, insert threaded fitting, weld or braze in place & screw in a drain plug or shut off valve. As far as descaling I'd remove the boiler & drop it in a small pail of the solution.

JohnB wrote:Who did you talk to about adding the drain? A welding shop? Is your boiler brass or stainless? Should be pretty straight forward.

Stainless boiler. I only asked one guy and had to describe it to him. He said roughly $100. I'll shop around some more next week.

JohnB wrote:As far as descaling I'd remove the boiler & drop it in a small pail of the solution.

I talked to another technician at Chris Coffee. This time they said to avoid tipping out the acid since it might soak the machine and damage some other parts. They said to remove the vacuum breaker and syringe in and out the acid (boiler enema?)

I took out the vacuum breaker with a 19mm socket. The hole is bigger than I thought and I was actually able to look inside with a flashlight and see the heater coils. They were "spanking" clean. So no need for descaling. Based on this positive result, I probably won't have another look for a year or so.

The S1 boiler is chrome plated brass so fittings would be easy to source at any plumbing outlet.