On the fence about descaling your espresso machine? See here...

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by dslambo »

Hi All.

So i'm through the entire disassembly of my 2009 LM GS3 in readiness for the rebuilding this week.

One thing reading plenty of pages here about should I descale? What about small particles going through the system? Is it really necessary?

Well, the decision to or not to is up to you, but for a machine (such as mine) where you have no idea on what the previous owner(s) have done with water care (or machine care in this case as well) I would recommend a complete removal of the boilers and heating elements. Why? See the disgusting lack of care that is in my steam boiler...

Steam Boiler Element

Boiler outside

Boiler inside

Boiler loose bits

This is the perfect use case for removing the boilers to descale and not to run a descaling agent through the machine. The shards that are coming out of the steam boiler are super brittle and break easily with simply touching them - hate to see what would happen descaling this with the machine all connected.

Hopefully this gives you a reason to either decide to pull your machine apart (especially if its second hand) or to have a professional look at descaling it for you.


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BaristaBoy E61

#2: Post by BaristaBoy E61 »

While there is no doubt it's a mess best dealt with by tearing it down, descaling and rebuilding as you are doing but I would still like to see what would happen to some of those scale particles you have collected if they were placed in a solution of citric acid for a couple of days in a Pyrex measuring cup.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

dslambo (original poster)

#3: Post by dslambo (original poster) »

Mate, what an awesome idea!

Since I have them drying on the bench on some paper towel - I will run some experiments to see what both vinegar and citric acid do to them.

Citric acid works better with heat - so I'll run in separate containers a hot and cold experiment on the particles dissolving.

Any suggestions to what you would like to see test wise?


dslambo (original poster)

#4: Post by dslambo (original poster) »

Whilst technically this isn't the loose bits dissolving, the GS3 has two heating elements in the steam boiler (one which isn't powered), and its been sitting in citric acid for about a week so you can see the results from just that. Only heat it had was the initial pouring into a Ball jar.

No powered element in citric acid for a week (same boiler)

Both elements together

You can see how much this has stripped it off the elements, but looking forward to testing the dissolving as well.


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BaristaBoy E61

#5: Post by BaristaBoy E61 »

That's some awesome results with the heating element. I've descaled our machine with citric acid without disassembly and the results have been very good. I was sure I'd have to take it apart since there was very little water pressure coming out of the hot water spigot due to severe scaling.

After the citric acid descaling the machine ran at least as good as new!

I can always get an indication of what might be happening internally by monitoring what the hot water spigot strainer has filtered out.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

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#6: Post by Marcelnl »

wow that is serious scale, the good (always relative) news is that it does seem to dissolve in citric acid. Since I noticed in my Faemina that the typical tap water hardness in my area creates a sort of scale that is hard to get rid off I started using mineral water (a sort w very low minerals) plus some potassium bicarb to buffer pH swings and have not seen scale since, same in the much more difficult to descale Urania. Prevention is key IMO.
LMWDP #483


#7: Post by Tony77 »

Ok, so now I'm paranoid. Those images of scale are going to haunt me for a few nights. I recently posted about long term maintenance fo my R58 after disassembling components of the brew group and noticing quite a bit of scale.

I think I know the answer to this, but is there any way to tell how much scale is caked on to the machine's internals without disassembling the boilers? And if I do discover something similar to what was growing inside your GS3, is there an at-home remedy (disassembling the brew group is the most intricate procedure I've performed on my machine).


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dslambo (original poster)

#8: Post by dslambo (original poster) »

Sorry Tony,

This is indeed the field of nightmares and not dreams. Mine is an extreme case tho, I would not expect that most peoples machines are this bad, but it goes to show you how water quality control is so important.

After letting this boiler dry for a few days - this is what shook out of it ....

Still a fair amount of crud stuck to the walls, and found a few floaties in the other pipes - so cleaning frenzy under way.

I don't know how to take apart an R58, but I can definitely recommend that the boiler removal gives you the best idea of what is inside your machine.

Not sure how your water is, but San Jose (CA) water is particularly hard and super chlorine levels (its soo gross out of the tap) so im not surprised about what im finding. The interesting part is the coffee boiler has none of this - only the steam boiler.

Hoping tomorrow I will get a chance to run some side by side experiments on the remnants I have collected from the boiler in dissolving the disastrous scale.


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#9: Post by jwCrema »

Hopefully you acquired the machine at a price that makes this endeavor worthwhile.

I'm using 100mg/L of Potassium BiCarbonate to improve taste (it works!) and to mitigate scale build up. It's the perfect win/win. I credit the late Dr. Pavlis for posts on this website that both brought back fond memories of my lab partners in Chem class and the use of KHCO3.

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#10: Post by HB »

dslambo wrote:The interesting part is the coffee boiler has none of this - only the steam boiler.
The water leaving the steam boiler is by definition distilled, so the mineral concentration can only go up. That's why you either have to treat the water to avoid scaling, or flush the steam boiler empty from time-to-time along with a preventative descale, assuming the water isn't too hard. The brew boiler is flushed with every brew cycle, so you only have to worry with incidental scale buildup for it.
Dan Kehn