Red buildup on La Pavoni heating element

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pomskis

#1: Post by pomskis »

Hello, I bought a used La Pavoni Europiccola '95 from FB marketplace a few years ago but since I was saving up for a grinder, it went unused for a long time. When I first bought it I tried to descale it with vinegar, there wasn't too much scale buildup at the time. I neglected it until recently when I finally purchased an Eureka Mignon Manuale/Notte grinder. Now I am going back to try and restore my La Pavoni but I found that the heating element inside it has this reddish speckled buildup in it. Is this rust? How can I remove it and properly clean out my machine? I am a little intimidated. Thanks for any responses.


jtrops

#2: Post by jtrops »

It looks like copper oxide.

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stefano65
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#3: Post by stefano65 »

That looks like an extreme over heated coil,
run without water and such,
I'm surprise if still reads properly.
Stefano Cremonesi
Stefano's Espresso Care
Repairs & sales from Oregon.

pomskis (original poster)

#4: Post by pomskis (original poster) »

This is a picture of it off, so the red is just what it looks like currently (without any heat). How should I clean it off if it is copper oxide? I ordered some citric acid which seems to be the general recommendation, I will try soaking it in that.

RobAnybody

#5: Post by RobAnybody »

That looks like an extreme over heated coil,
run without water and such,
Stefano means that it looks like the element overheated at some point, and it might not function any more.
I'd trust him on this he is an expert.

I would only expect it to be copper oxide if your heating element is a brass/copper one, though from the image you show the base looks like a steel version (both could be possible with the build year of your machine, but a quick look under the base can sort that out).
cheers,
Rob
LMWDP #647

pomskis (original poster)

#6: Post by pomskis (original poster) »

Oh I see! That's strange, I don't believe I have ever heated it up without water inside it before, but maybe I did and don't remember. I don't think it looked like that when I got it, it was more white and had calcium buildup on it. This one is a refurbished Europiccola so I guess potentially the seller could have replaced the heating element, but I'm not sure. I will take a look under the base later today.

pomskis (original poster)

#7: Post by pomskis (original poster) »

I took off the cap on the bottom of the machine and found that the heating element is indeed copper and not steel, so I think I'll try to descale it with vinegar and water first, hopefully that will help. If it doesn't work I may try citric acid but I am nervous about using that with the chrome machine.

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homeburrero
Team HB

#8: Post by homeburrero »

pomskis wrote:the heating element is indeed copper and not steel, so I think I'll try to descale it with vinegar and water first, hopefully that will help. If it doesn't work I may try citric acid but I am nervous about using that with the chrome machine.
I don't think you should descale. A red appearance is normal for copper, perhaps redder than usual due to recent descaling, or overheating as Stefano suggested. If it is copper oxide you don't want to remove that, but rather let it develop as a protective layer. Initially the copper will react with dissolved oxygen in the water to form copper(I) oxide, Cu₂O, which is reddish, then further oxidizes to copper(II) oxide, CuO, which is blackish. These oxides will give the copper a dull brownish thin uniform patina that is protective. You want to keep this layer and not strip it away by descaling.

I see no scale deposits on the element or boiler that would indicate a need to descale. I think I do see a whitish glassy deposit on the brass base beneath your element. Not sure what that is, but might be silica, and if it is you can't remove it by descaling.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

Smo

#9: Post by Smo »

Citric acid and vinegar break down copper. Leave as is.

pomskis (original poster)

#10: Post by pomskis (original poster) »

homeburrero wrote:I don't think you should descale. A red appearance is normal for copper, perhaps redder than usual due to recent descaling, or overheating as Stefano suggested. If it is copper oxide you don't want to remove that, but rather let it develop as a protective layer. Initially the copper will react with dissolved oxygen in the water to form copper(I) oxide, Cu₂O, which is reddish, then further oxidizes to copper(II) oxide, CuO, which is blackish. These oxides will give the copper a dull brownish thin uniform patina that is protective. You want to keep this layer and not strip it away by descaling.

I see no scale deposits on the element or boiler that would indicate a need to descale. I think I do see a whitish glassy deposit on the brass base beneath your element. Not sure what that is, but might be silica, and if it is you can't remove it by descaling.
Thanks for the detailed reply! The glassy substance at the bottom was scale buildup but I think there was also some moisture trapped inside, I'm a little worried this might have caused some rust. I realize the boiler is made of brass/copper and should not rust but I think there may be a rusty spot at the bottom (a little hard to see but it's the reddish spot in the middle of all the white buildup at the base of the machine).

Unfortunately I read your reply too late and already descaled it with a weak concentration of vinegar and water, but it didn't remove any of the red stuff. However it did make the rust(?) spot at the bottom more prominent and red, although the rest of the inside of the boiler seems to be in pretty good shape. Is it possible for the machine to rust inside the boiler at the base? And if so, should I take it apart to try and remove it? I can take some more pictures tomorrow if it helps.