Hi all,

I recently picked up a second la Pavoni for work. Bought the machine off eBay and when it arrived it really needed some TLC. Overall, mechanical, it was fine but I'm having a devil of a time get scale off the heating element and boiler. I have run through 2 lots of descaler, and vinegar, and still there is noticeable white flakes inside.

I read somewhere that it's not a good idea to operate the lever while descaling as this can erode the seals when using citric acid? Also can I leave the descaler in the boiler overnight or might this attack the seals? Any suggestions on a strong descaler that won't cause side effects to seals or machine?

In the process of descaling (and operating the lever) the shower screen came loose with the portafilter seal. What came out from under the screen was a black oily substance, almost like old coffee grounds mixed with...oil. The top of the Teflon piston was covered in the stuff and when operating the lever black pieces would flush out. anyone experienced something similar?

It's my first millennium machine and I'm used to the old brass piston, this Teflon coated plastic thing doesn't look like its going to last as good as my old pro.

To be frank, with a used machine I wouldn't worry about damaging the seals. It's very likely that they need to be replaced either way. Especially with a machine as simple as the Pavoni, I'd always go the rebuild-route. It doesn't really take more than an afternoon to take it apart, clean it, and put it back together with new seals. And the feeling of drinking the first shot out of a machine you KNOW is completely clean is worth it.

Regarding the Plastic-Piston-Thing... yea I don't trust those anymore, either...

I agree with Marcus. I just assume that every Pavoni or Elektra I buy needs a new gasket kit then I'm not disappointed. I would give the citric a miss here and use a proprietary liquid concentrate like caffeto that actually dissolves scale.

I usually use tartaric acid..

Doug & Barb (orphanespresso) have a video http://www.youtube.com/watch?v=QOhmonGoNq4 showing an agressive descaling. He sticks with citric, and only leaves it for an hour, although he does use a slightly stronger than 1 Tbsp/L solution.

Another of their videos, http://www.youtube.com/watch?v=BewMTXmKHds describing the routine descaling of a Cremina, advises running some of the descaling solution through the group.

Thanks for the info guys, I ended up taking the group off again and cleaned it properly. Looks like the boiler/bass seal is starting to leak (strangely it only leaked/wept when I had descaler in the machine at working pressure, with water again it seems fine), so that's the next task.

Um, how do I get the base off? It seems loose the whole way round till the back where there looks like a black plastic tab that needs to be pushed in to release. Am I on the right track?

Thanks