Water, Scaling and Descaling with HX machines? - Page 5

[Ozark_61]

Whew - that took a while. I finally got around to the local brew supply shop here and bought some citric acid. Descaling can be a pita! That, and having the temp drop too much when filling with descale solution, vacuum breaker falling, and then showering the inside of the machine with descale and subsequent shorting out mains current made for a long evening / morning!

Benefits? Looks like my giotto's steam wand is no longer drippy without a hard tightening and the lever is much smoother too boot.

I noticed that while soaking the boiler and flushing the HX - the water went from dark green to light blue/green after several flushes of the hx through the gh. Is that an indicator for decreasing levels of scale? Also, I noticed metal particles in the water in the flushed water. With a strong overhead light, I could see the tiny particles glittering through the water in the flushing cup. Is this normal / harmful / temporary?

Geoff

ps - clean your in-tank water softeners (link).

PPS - I just thumbed through the old posts about descaling and realized I shouldn't have backflushed the machine per Jim's comment that a squeaky clean machine should not be introduced to an alkaline detergent. I had more flecking (did look like chrome bits) before the backflush, so I don't think it did much harm.

I would recommend adding that point to the HX descaling instructions!

[jgriff]

I also finally got around to descaling my machine recently after about nine months of ownership. I also backflushed with detergent in conjunction with the descaling, before I overfilled the boiler or started any of that. I don't know if it caused any problems or not. Everything seems to work fine, but something odd did happen.

I drained the boiler first and overfilled it with descaling solution. Once the boiler was full and soaking, I flipped the lever to flush the HX and grouphead. I ran some fluid through until I could see a bluish tint and then stopped to let it soak for at least 10 minutes. I'm not sure when it started, but at some point I got more water than usual running out of the discharge tube into the driptray, and it ran kind of continuously for a while. Then, the next time I pulled the lever to flush more fluid through the HX and grouphead, the pump ran for at least 10 seconds before anything came out and it sounded like the water had all disappeared from the line.

When I put the lever down that time, it again dripped all the water out and seemed to be empty again next time I pulled the lever. Along with this I could hear a constant kind of boiling sound like when the heating element is on, but it wasn't. I figured my HX was boiling dry for some reason and it wasn't doing much good anyway, so I gave up after a couple of repetitions and just let things soak.

Even after I finished descaling and flushing, this behavior continued for a while. I would flush the HX before pulling a shot and while the temp rebounded the water would all run out of the discharge into the driptray so it sometimes took a while before I got first drops from the basket while the HX or grouphead was re-filled. I don't know if the water had even been heated sufficiently, but the shots didn't seem too terrible aside from having a donut extraction that I hadn't had before.

Now, a few weeks later, everything seems fine. Anita's behavior is back to normal and my extractions are looking very even again. I suspected that some chunk of scale must have got lodged in a seal or mechanism in the group, thus keeping the valves slightly open and allowing all of the water from the thermosyphon loop and perhaps the HX to run out. I guess it finally found it's way out and things are good again. Still, I don't know if that would help to explain the donut extraction. I think I should probably try descaling just the HX again as I didn't flush it that much. Does anyone have any ideas or input on this behavior? Thanks.

Justin

PS Not sure if this post belongs in this thread. I can start a new one if it seems appropriate.

[cajun_brew]

If you are good on scheduling, the ideal is to use water at around 5 grains, run distilled into the boiler every week to keep it clear, and descale just the HX circuit quarterly. That part of the machine descales just like a single boiler, since the HX has a relatively small volume and is entirely filled with water. The boiler, being partially filled, will form scale at the rim, and on the autofill rod because it has a current. So the descale has to be done by force overfilling the boiler, which is the main pita.

After descaling my boiler a few weeks ago, I ran distilled water into the boiler and after 1 week I was flushing it out to replace it and it had a brown muddy look to it. Is this normal? I"ve never seen this before and can"t remember reading a post where this was happening....

thanks

[mp]

Thanks for the link, Teme. Dave's made some good points, specifically here.

Anytime one removes the casing, there's a risk of electrical shock should the owner neglect to unplug the machine. One can add the usual lawyerly warnings about risk of death, fire, destruction of property, etc., but the fact is the manufacturer doesn't certify these machines as "consumer repairable." In addition to the potential personal risk, accidently pressurizing the boiler with the pump would be a very bad thing for the machine (it's only factory tested around 2-3 bar, not 16 bar! And the pressurestat is accustom to only ~1.2 bar). Of course, I keep the steam wand open during the entire operation, so that's not possible, but if somebody forgets...

Chris Nachtrieb once said to me that descaling the HX is really what matters and that's simple. He argues that few actually drink the steam boiler water and a little waterline scale isn't worth getting excited about. I have to agree with him and Dave, running descaler through the HX and then filling with descaler / flushing the steam boiler is a no-brainer and would deal with almost all of the scale build-up.

I have had my Isomac Tea ll for about 3 weeks now. I got it second hand from a chap on eBay. It is 8 months old and by my sellers own admission it was back flushed every two weeks but never descaled. I have backflushed it myself a week ago and today I decided after reading this fine post that I would descale it. Not being very mechanical myself and therefore not wanting to void warranty or get myself into a heap of trouble I decided to follow Dan Kehn's and Chris Nachtrieb's advise and just descale it simply.

I started by doing another back flush until the water drained out clean. Then I shut off the machine ... took out the water reserve and and washed the 3 liter container with dish washing soap and water. After it was squeaky clean I put it back into the machine and heated up some water. I use 4 parts reverse osmosis and 1 part soft water. I have a whole house water softener and a reverse osmosis water filtration system attached to our fridge and a tap on our sink. This combination is better than just reverse osmosis water as I found I did not like the taste of the coffee just by itself. After I added the soft water to it the taste of the coffee seemed to get fuller and slightly sweeter. So ... after heating up the water in my 1 liter pitcher I added 2 tablespoons of citric acid to it and poured it into the water reserve. I repeated this two more times until it filled up. I then turned the machine back on and let it warm up for 20 - 25 minutes. I then flushed the group once every 10 minutes. I kept doing visuals on the water from the HX for signs of scale. I found that there was still scale particles on it after 6 flushes so I continued to do them for another 6 flushes. At this point the scale was very visibly diminished. I will accompany this post with some pictures showing the progression of the water and the scale build up. I filled the machine with 2 more liters of water with 2 tablespoons of citric acid per liter.

At this stage I let the water warm up a bit for 15 - 20 minutes. I then flushed 2 liters of water from the boiler. My boiler capacity is 1.4 liters and figured if I flushed 2 liters out I would put in enough water with Citric Acid in there to begin a good descaling. I left the boiler for 2 to 2 1/2 hours to soak in the heat. Then I began alternately flushing the group and water from the water valve repeatedly until I had flushed 4 liters of water. As 1 liter of the Citric Acid water was flushed out I would refill with Reverse Osmosis/Soft water combination so that I would eventually flush all of the Citric Acid water out of the system. One thing I did notice ... every once in a while I opened the steam valve to allow the Citric Acid water flow through the steam valve. This water had a real odour to it. The more I flushed out the Citric Acid water the better the water from the steam valve smelled. To make a long story short after I flushed 4 liters of clean water through both the boiler and the HX unit I called the descaling process complete. Looking back it was relatively simple but time consuming. Check out the attached photos of the water.

Apparently my pictures are too big to post here. I will work on them and see if I can post them later. Hopefully I offered a bit more insight on descaling for the beginner.

A quick note on water. Distilled water is the purest water anyone can drink. I has 1 or 2 parts per million of solids. It is slightly Alkaline in nature. Reverse Osmosis is generally about 15 to 30 parts per million of solids. It is slightly acidic in nature. The reverse osmosis water molecule is a bit strange in shape. The distilled water is the purest formation molecule and arguably the best water anyone can drink. Having said that the best water I've had in terms of making espresso is a 4 to 1 reverse osmosis / soft water mix or 4 to 1 distilled water /soft water mix. I choose the 4 to 1 reverse osmosis / soft water mix as its easy to come by as I have a whole house water softener and reverse osmosis under the sink filter. The distilled water I have to process myself by the gallon.

[mp]

The first picture shows what the water looks like after 4 liters of water have been used to flush out the Water / Citric Acid combination from the HX and group.

The second is a picture of what the water looks like after the 3rd or 4rth flush of the HX.

The first is the color of the water after the first flush of the HX ... notice the blue/green hue of the Citric Acid.

You're goal is to make the water look like the fist picture after you've finished flushing the water with the Citric Acid powder out of your machine.

I hope this will help you out.

[mp]

Post note.

This morning a made some newly acquired Honduras Chizpatchitis organic freshly roasted and flash frozen yesterday for my wife and I. I noticed the behavior of my Tea ll changed after the de-scaling ... the lever that brews the coffee seems to move much more freely. The taste of the coffee is the best I've had yet on the machine. The de-scaling although simple was time consuming but well worth both the improvement action of the lever and the improved taste if the coffee.

I highly recommend it.

[WR]

I'm getting ready to do the first descale of my Vetrano. I've had my machine for a little less than two years and am embarrassed to say that i have not descaled (audience moans in the background). I'm in NYC and we have pretty soft water that i run through a whole house solid block charcoal filter with fiber media just in front of my intake.

I just installed Eric's adapter and using it along with reading all of the great HB posts on the subject has greatly steepened my learning curve. I'm experiencing low idle temps (108.5-109 with a BP of .93-1.15) and VERY long ramp up times from 185 (4.5-5 minutes). I noticed what looks like a little scale developing on the top mushroom nut just above the gasket and can sometimes find a drop of water. I'm going to pick up a 36mm wrench and pull it. I have a feeling it's going to look like Dan's ugly BEFORE photo of the pre-descale mushroom.

Either way i will descale the HX this weekend. I think i will just descale the HX as we are espresso and Americano (water from the flushes) drinkers and don't use the steamer more than five time a year. My question concerns the mushroom.

1.)If it's badly scaled will multiple passes of a normal descaling procedure remove all of the hardened crystal or should i disassemble the mushroom, gicleur etc and soak them all separately first? If so, any tips? I assume that if a soak is required, that i should not include the chrome top nuts in the acid bath!
2.)should i not pull the mushroom without a backup silicone gasket or will it likely be OK to reuse?

Also I have AirOSwiss EZCall for descaling dehumidifiers. does anyone know if its the same as Dezcal? It is made by Urnex and lists the same ingredients, but i should just call Urnex i guess.

Thanks to all Will

[erics]

Personally, I would advise against descaling the Vetrano using the installed rotary pump and here's why:

This PARTICULAR application has a very small (6 x 4 mm) suction line on the pump and, because of that, requires a positive pressure, preferably regulated, of around 3.0 bar (40-45 psi) to operate free of cavitation. The pump itself has 3/8"-19 BSPP female threading at both the inlet and outlet ports and would be fairly easy to adapt to depending upon your mechanical ability (only the inlet/suction port is of concern).

edit on 08/19 - the suction and discharge lines on the Vetrano are 5 x 3 mm

As configured, the pump/machine combination CANNOT take suction from a descaling solution container resting on your table top without damaging the pump.

Scale buildup on the mushroom assembly (by itself) won't have much impact on thermosyphon flow or heat transfer but is MOST DEFINITELY a good indicator of scale formation elsewhere in the hx loop. Scale buildup on the mushroom chamber walls - typically in random spots - will have an effect proportional to the area covered over by the scale.

I would be willing to send you a small pump that you can use (for s and h costs) provided you take pics and report on the experience here.

[WR]

Interesting... i was worried about the ability of the rotary pump to suck that much water without positive pressure and have seen conflicting info. Thank you for the kind offer to lend a pump and i may take you up on that, but what type of pump would you recommend? It probably makes more sense for me to purchase one if it's not too dear as I imagine it should be a semi-annual or at least annual event. I will gladly post some pics in either case.

Thanks,

Will

[erics]

The pump that I would send is a Greylor LGP - http://www.smartcart.com/greylor7...cgi?item_num=LGP-1
It is new and I would at least test it out here in Maryland first.

I was/am in the process of developing a "descaling kit" and you, sir, would be the guinea pig for the major component.

[WR]

In that case i will gladly serve the cause! Put as much of the kit together as you like and PM me with details and we'll get it going.

Regards,

Will

[erics]

The "loaner" to you would consist of:

(a) Greylor LGP Pump (previously referenced)

(b) 5/16 OD x 3/16 ID flexible tubing - probably about (2) 4 foot sections

(c) section of 6x4 mm tubing w/nut to take the place of pump discharge line
(Note that 6x4 mm teflon tubing will be a nice tight fit inside of 3/16 ID flex line)

(d) 1-7/16" and 7/8" thin, short wrenches (for removing mushroom and mushroom cap)

(e) tool for removing/reinstalling gicleur (7 mm nut driver and 4" of 3/8 OD tube)

(f) Instructions

Send me your mailing address via normal email - erics@erols.com

[Kuban111]

What a sacrifice in the name of science.


Ill be looking for the results & feed back myself.

Funny this is being discuss I've been thinking about this same thing lately.

Erics is the bomb dig ity

Michael

[erics]

Thanks M.

Here's da kit in its initial form:


More later as family is bugging me for chow.

[edwa]

Does anyone know if the Volante also suffers from a small suction line? I'm waiting for word from Jim at 1st line about the size but I thought I'd ask if anyone has descaled a direct plumbed Volante.

Eric how has the pump kit worked out since your last post?

[edwa]

For those that want to know, I just got this reply from Jim on the Volante:

3/8" British - it is enough to suck the solution

[erics]

Ed - be just a LITTLE bit cautious. The "mains" connection on the great majority (if not all) home machines is, in fact, 3/8". The Italians term it a 3/8" Gas thread and this typically means 3/8" BSPP threading. There is no problem with the 3/8" size and no problem with the BSPP threads.

The problem occurs in the transition from this 3/8" size to whatever is attached to the pump. In the case of the Vetrano, the 3/8" transitions to a M5 x 3 tubing - that's 5 mm OD and 3 mm ID. This works just fine as long as one is supplying the Vetrano a positive pressure - say 2.5 bar or around 35 psi. When one tries to operate the rotary pump in that machine simply by taking suction from a nearby stationary reservoir, the pump will cavitate, i.e. this DID NOT work:

My solution to the descaling adventure DID NOT WORK either because of the check valve incorporated on our machines at the entrance to the hx. My little pump could not overcome that valve whereas the machine's pump, whether it be vibe or rotary can easily meet the pressure reqts to pass through that valve.

However, I have not given up just yet - but keep in mind that the idea is to have a complete "kit" that ANYONE could EASILY use - not something requiring the Snap-On Tool truck and a regiment of espresso machine technicians.

[sweaner]

Eric, I am running a Vetrano from a bottle without positive pressure and it does work. I have been assured by Chris that it is no problem, as long as the machine does not have to draw the water upward. I am not sure what went wrong with your setup, which is similar to mine.

[erics]

Scott -

About the only thing I can honestly say is that I'm glad it works for you. That was a loaner Vetrano I had which I was running a few tests on and the pump was surely cavitating when I tried to take suction from the container - both by sound and the miniscule flow I was getting through the group.

Taking suction from the "make-shift" reservoir I fabricated is the ideal way to descale.

[Balthazar_B]

Eric, can something like a Flojet BW1000A (http://www.1st-line.net/cgi-bin/category.cgi?item=BW1000A&type=store) be used as the pump in your descale kit? I have an old one lying around from the days before I plumbed in my Vetrano. And they cost a bit less than your cool lab pump!