Descaling boiler makes taste difference?

Need help with equipment usage or want to share your latest discovery?
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#1: Post by Spironski » Mar 04, 2008, 8:59 pm

Two weeks ago I got a secondhand Major, it replaced my Aristarco SE/N (a Super Jolly). But I must say I was disappointed with the taste it gave: it was clearer, less creamy, round and chocolatey. When I replaced the burrs on the Major things got better, but it still wasn't as full-flavoured and round as it used to be. So I tried my Super Jolly again, and what do you know: it wasn't better than the Major (thank God!).
So was it the coffee I used? I tried new beans, but it still did not taste as it used to. Or was I kidding myself, and did my taste progress? I was lost.
And all of a sudden I knew: I descaled my machine about two weeks ago! Can it be that descaling generates such a taste difference? Has anybody had the same? Did your espresso taste worse after descaling?

One thing I noticed, is that after the descaling my machine started to drip when making espresso. When it is under pressure there are drops coming out of the.... uh... (how do you call this?:) the backflush-exit? (you know, the tube-like thing underneath the group?) Can it be that an O-ring went bad, and that I am losing pressure? If so: can I replace it myself?

I hope somebody can spread some light on this...



#2: Post by popeye » Mar 04, 2008, 10:09 pm

I'm going to hazard a guess - but it's a guess. I think my machine once leaked after a descaling because i didn't descale it completely and some of the scale came loose and jammed a seal.
Spencer Weber


#3: Post by djmonkeyhater » Mar 04, 2008, 10:25 pm

what machine are we talking about?

how old is it?

what was the descaling method? (in some detail)

can you send a picture of where the machine is leaking?

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#4: Post by shadowfax » Mar 04, 2008, 10:36 pm

Is it right to assume you're using the La Scala Butterfly in your profile? If you descale and/or backflush the machine with detergent, you purge the coffee oils out of the group assembly. This can, potentially, cause a leak in the machine. In my E61 of former days, I always noticed that after detergent backflushing the grouphead would resist motion a lot, and it would even squeak. I never noticed any leakage, though, but it seems like this could happen. Coffee oil is apparently what' supposed to lubricate (and probably help seal) the grouphead. Thus, the squeak goes away after 4 or 5 shots, and the motion of the lever gets smooth again.

Of course, it's possible, if your machine is badly scaled, and you descale, that a fragment of scale could be knocked off of the inside of the heat exchanger or the inside of the grouphead. This could then be stuck in your grouphead, preventing it from fully closing off the backflush chamber when you are brewing. If that's the case, I think it will mean that you will need to manually take the grouphead apart and clean it by hand... I wouldn't take on that task lightly, I think that the grouphead is generally sealed with loctite or some other type of sealant.

Hopefully the problem goes away before long. If not, I guess you could always try descaling the heat exchanger a few more times in the hope that it will dislodge whatever is preventing the seal.

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#5: Post by Spironski » Mar 05, 2008, 8:30 am

Okay thanks guys,

I will do another descaling then. Perhaps some really good detergent backflushes first. My machine is indeed the La Scala Butterfly, it is 4 years old, I have it for 6 months, so this was my first descaling. I emptied the boiler, then filled the watercontainer with what I think is some sort of acid-solution (I bought it in a bottle from a espresso-shop), let the boiler fill up again to descale, and then did some "brewing" so the HX could descale. Repeated this a few times, in between let the machine "soak". Afterwards emptied the boiler and did some heavy flushing everything. All in all it took me 2+ hours.

Oh, by the way: the machine is not so much leaking on a "wrong" spot, the drops come out at exactly the same exit as when you do a backflush. Sorry for describing this so crappy, English is not my native tongue I am afraid...

But has anybody noticed a decline in taste after descaling? And can it really be that a slight drop in pressure means less taste?

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#6: Post by Spironski » Mar 07, 2008, 8:07 pm

Okay, what it boils down to :D : the leaking has diminished, so that's fine. But this is the big improvement: I lowered my boiler pressure! Duh!
I noticed that after the descaling (which must have been really necessary), that my flushing required a lot more time, so it seems that the scale inside the HX acted like some sort of insulation. Now I have lowered the pressure by 0.2bar, I think everything is where it should be. I got my yummie taste back! Never knew it would be of this much influence...( I mean descaling :oops: )


#7: Post by popeye » Mar 07, 2008, 10:48 pm

If you had enough scale to act as insulation - and with a used machine, you may have - there is a definite possibility it was a chip of limescale that was blocking the valve from closing. With use, the chip will degrade, but running some descaler through your group - backflushing with descaler - may help. It's difficult to clear the lower part of the three way assembly though, because to get the descaler in there you have to put the lever all the way down, which actually just allows the descaler to drain through. Some drips of descaler will remain, however, and may be enough to get rid of that chip. I'd recommend backflushing with descaler a couple of times, leaving the machine for two to six hours, and then doing a thorough water backflush. Anyone else have any comments?
Spencer Weber

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#8: Post by mrgnomer » Mar 27, 2008, 4:26 pm

The HX line goes through the boiler. If it has enough scale in it that some came off during a chemical backflush to block open the 3 way valve I'd think the boiler itself has some scale in it as well since the same water was used in both.

I've read where scale buildup on the outside of the HX line will insulate it and cause it to heat more slowly. Longer rebounds with a scale build up, I would imagine and less flushing. Strip some of the insulating scale away and rebounds would be shorter with more flushing after idling. As well, since a lot of the scale builds up at the top of the water line, it's good to overfill your boiler with descaling solution to get rid of it.

Depends on what you use but usually the descaler needs a couple hours or more to work in an operating temp boiler. Just a quick soak and flush might not have done as much as a longer soak unless your descaler is commercial strength. I imagine you'd be able to see the quality of your boiler water by drawing some out of the water wand and seeing if there's stuff floating in it. I'd check the water wand screen as well for big flakes of floating scale that might have got stuck.

Do you know what kind of water the previous owner used and what kind of regular maintainance they did to the machine?
LMWDP #116

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#9: Post by Spironski » Mar 27, 2008, 9:12 pm

Okay, because I got my yummie taste back by lowering the temperature, I did not bother to do another descaling yet, I have to admit :oops: . The leakage is a little less after these two weeks, but there is a thing I can't explain: the machine is leaking heavier when I am brewing than when I do a backflush. Does anyone have an idea about this? When I backflush it is only a few drops, but when I am brewing it really drips...

The former owner lives on the other side of the country (which, by your standards is still quite nearby (300 km.) :D ), so I do not know what kind of water he used. I imagine that his maintenance was not all that thorough.

The first descaling took me two hours. I think I will do another, extra long, descaling one of these days. Unfortunately I don't know how to overfill the boiler. The descaler I use is meant to be used quite cool, so not in a heated boiler. Supposedly it will start to foam or something.

Well, thanks again for helping, and I'll report back when I did my second descaling...

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#10: Post by mrgnomer » Mar 27, 2008, 10:23 pm

Disconnecting the probe will activate the refill. Open up the steam wand and when water starts coming out you've over filled. That or unplug the machine and put it on its back, let it sit there a while and flip it to the other sides letting it sit for a while between flips.

When you say more water is coming out of your machine while brewing as opposed to descaling do you mean it's coming out of the 3 way? If your 3 way is lever actuated maybe the seals inside need replacing. It might not be a bad idea to take the group apart and see what it looks like inside. You could check if it's stray scale jamming the 3 way open that can be cleaned and/or if the seals are gone.

This is a good reference to the internal workings of a lever actuated e61.

E61 Group Espresso Machine: Is its reputation justified?
LMWDP #116