Edit: Just turning this into a rebuild blog at this point as I keep finding more to do!

Hi, I have had my S1V1 for about five years (bought used). It recently started acting up where, if I started it cold, it would leak water from the boiler area until it heated up, then it was ok. Well now it just leaks until the 60 second fill timer is up and errors out. I decided to tear it apart and start looking and this is what I saw: It did finally heat up and work again during this video, but I still wanted to find the leak or issue so tore it apart further (see attachments). I found a kind of black scale all in the boiler and on the heating element, temperature sensor, and on the tip of the fill probe. Also found similar black scale on the group boiler heating element (but strangely not the actual boiler walls). Is this something I can just dunk the whole boiler (probes, heating element, and all) in cafiza or something to get rid of all the scale? Or do I need to disassemble everything first? I already found and ordered the gaskets. Any advice would be greatly appreciated!

Not sure when the video was taken, or during the warming up, or after, but seems to me the vacuum breaker is leaking.

Is your water softened by any chance?

You'll be able to wire-brush the level probe back to "shiny" and maybe get the boiler fill routine working properly. Then replace the vacuum breaker so that it isn't contributing to the leakage. Then start testing again to see if all of the leakage was coming from the vacuum breaker or if the boiler is indeed leaking at the element seals (it's hard to tell in the video, it starts off with the entire boiler-top wet).

DaveC wrote:Is your water softened by any chance?

I am using re-mineralized RO water exclusively

JRising wrote:You'll be able to wire-brush the level probe back to "shiny" and maybe get the boiler fill routine working properly. Then replace the vacuum breaker so that it isn't contributing to the leakage. Then start testing again to see if all of the leakage was coming from the vacuum breaker or if the boiler is indeed leaking at the element seals (it's hard to tell in the video, it starts off with the entire boiler-top wet).

Ahh ok I did not know what that piece was called. I thought it was some kind of overflow valve but then I saw the overflow valve too so had no idea. Is that item broken or you think just leaking? It had a weird lock washer thing under it so it wasn't flat with the top of the boiler and that seemed strange to me.

Close up of the vacuum breaker

Clean up the white Teflon seat and get a correctly sized FKM/Viton O ring (or silicon, if you can't get FKM) and you can fix it for a few cents.

Exactly as DaveC says, a few cents and you're good for 3 to 8 years. Beware to not scratch the Teflon or brass seats. Scale is limestone and abrasive. Use citric acid to dissolved the lime, and a tooth pick and toothbrush as soft scrub tools. For final polish you can use toothpaste, it has mild fine abrasive. Or silver polish. For reassembly put thin coat of Dow111 or other food grade silicone on threads, o-ring and sealing surfaces. This will extend service life and make cleanup easier next time, 5 to 8 years out.
-Deuxinfuso

I was already making an order and this part was like $15 so just went ahead and grabbed it. I think the scale had built up around the O ring so much I was having a hard time getting it off.

One more question of you helpful folks: I have the entire boiler out and plan to descale all these parts with citric acid. Is it ok to just dunk the entire boiler (heating element and all) into the solution? Is there any preferred ratio to use?

Oh and you suggested molykote on the threads, is that in lieu of teflon tape? There was teflon tape all over these things I took out and it was annoying and didn't seem like it properly sealed anyways.

So I started this and it's working great, but just want to double check before I get too far, is it ok if it strips the shiny coating off the outside of the boiler?