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Descaling Boema 2 Goup

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  • Descaling Boema 2 Goup

    Hi all, I have picked up a cheap 2 group Boema to play around with and I am unsure how to go about descaling it. I have read that commercial machines need to be stripped to descale, but is this only the HX, or dual boiler as well?
    Another strange thing is that the water is coming out blue... so I havent tasted the coffee yet.
    Any ideas as to the blue water??

  • #2
    Re: Descaling Boema 2 Goup


    Id be stripping it - simply to ensure there are no lumps of scale left which can come loose and block jets, solenoids etc..... It is just a far safer way of removing god knows how many years of scale build up....

    Im not aware of any Boema dual boilers.... what model is it.

    And the blue stuff - if its dark..... probably copper sulphate or copper chloride possibly caused by someone using sulphuric or hydrochloric acid to clean the boiler..... rather than citric which will produce a very pale blue/green colour from the dissolved copper.


    • #3
      Re: Descaling Boema 2 Goup

      Ill put a photo in... Ill be taking the lid off it this weekend anyway, so Ill find out then.
      Is the copper sulphate or copper chloride harmful at all?

      **Picture removed 29/11/2015 due to copyright query**


      • #4
        Re: Descaling Boema 2 Goup

        Yep, you dont want to drink too much copper. Thats why passivating the boiler after descaling is good practice. Anyway. youll know when its re-passivated when the acid small/taste vanishes and youre left with clean steam and clear tasting water.

        You may need to flush the steam boiler contents a couple of times to remove all the residual acid.

        Welcome to the 2-group club!


        • #5
          Re: Descaling Boema 2 Goup


          Dont know about how harmful they are..... (assuming it IS what they are)....

          But I would be giving it a very good flush thats for sure (because there might be some acid still in there). They may have also used CLR.... which will give a blue colouration....

          If they have used anything other than citric acid it leaves a "bad taste" which is hard to eliminate.

          Look forward to the photos.


          • #6
            Re: Descaling Boema 2 Goup

            Congrats, Faed. Another snob with a 2-grouper in the home.

            Its been a long time since I did 5th form chemistry, but sufuric acid will turn copper blue -- and I certainly would be flushing, and flushing and flushing.

            When you get to the internals, remove some of the accessible pipes, and look inside them. Any scale will be evident. There usually is.

            If it looks bad, a descale of the boiler and heat exchangers along with pipes is in order.

            The Home barista forum has some pointers on descaling these sort of machines, except, of course, you have two heat exchangers to deal with.

            Keep us posted.



            • #7
              Re: Descaling Boema 2 Goup

              Hmmmm...lots of people seem to go running offsite unnecessarily to o/s special interest coffee websites looking for expertise that exists right here in this country and on this site.....

              Are you talking about water coming from the groups, or water coming from the  boiler?

              Where / Who did you buy the machine from?
              a) is it "ex catering"  or
              b) have you bought it from another private individual

              If it is straight from a catering site, it will IME be very unlikely that any kind of substance has been placed into the boiler - for the express purpose of "descaling" or cleaning out the boiler.

              Catering people simply dont do that.

              If therefore, it is ex catering, it would be more likely that the grey or grey blue colour coming from the BOILER WATER spout then is most likely the result of  a milk suck back, through a steam pipe, back into the boiler. This is common enough and simply indicates poor management of the equipment.

              No one in the commercial situation will descale a commercial esp fit water softeners or scale inhibiting water filters to the inlet water line & therefore, you do not descale. If you do not regenerate softeners or replace scale inhibiting cartridges, there will eventually be a scale problem however...

              Scale will live happily and inertly inside a commercial espresso machine long term, depending on the quality of the incoming water supply, until such time as blockages eventually start to occur. This could be many years down the line where the water is "good" or, within a couple of years where the water is quite hard.

              At that point the owner needs to decide what to do. It is not cost effective to descale old war horses and place them back into service so mostly, this means the machine will be "passed on".

              It is less time consuming and easier to use one of the proprietary scale removing  substances sold by companies that manufacture or distributing things like "group head cleaner" etc, than it is to physically strip a machine down to the last copper pipe and try to physically descale.

              Some machines are so contaminated with milk suck back or chemical suckback (such as through soaking steam pipes in chemicals or co*%a cola etc to try and remove milk scum build up), that even a manual strip will not stop the things stinking like a dead body...weve had 2 machines in the last year that we condemned as not commercial viable to repair for this reason.

              But what I am describing is 2 separate problems. One is the build up of scale ( which wont do anything but eventually start blockages...but the water will run quite clean and will not stink and the other, is contamination of the boiler through incorrect management, usually by milk or co called cleaning substances.

              The best form of protection (before you buy), is simply to run some water out of the boiler through the hot water tap and look at the colour and smell the water. Also, open the steam tap and smell the steam.

              If the water is diScoloured as you have found, and it and the steam stinks, I would hesitate to purchase because while a "mild" case of contamination can be cleared to a reasonable extent, a heavy case of contamination could result in a machine that will never be fit for the purpose again.

              You cannot tell how scaled up a machine might, or might not be, because as already stated, scaling blocks things up, but it does not show colour or stink.

              May I suggest that the first thing to do is to forget about descaling for the moment. If the machine flows water through its various outlets without problem, then it actually isnt an issue at the moment.

              Rather, do those couple of checks I suggested above (look at water from boiler,smell it and steam, compare water from boiler to water from groups), and if the problem is deemed to be boiler milk contamination etc, go through the process of running a CLEANING solution through the boiler.

              I guess the same will apply if the machine was purchased from a private individual rather than a commercial situation, because even though it is then more likel that someone MAY have put some kiond of chemical into the boiler, I think the appropriate course of action would still be to run some cleaning solution through it to see if that clears the discolouration.

              As always the KISS principle applies..keep it simple (& stupid)...and....why do something you may not need to do?

              We can sell you a very good cleaning solution to try. Oh and of course if the cleaning solution also ihappens to include a descaling agent, then you are killing 2 birds with one stone although as I have already suggested, I think your primary problem is not scale but somrething else.

              Hope your machine is salvageable.



              • #8
                Re: Descaling Boema 2 Goup

                Thanks heaps for the replies,
                I think I have bitten off more than I can chew, but I tend to do that quite often. At least Ill learn a bit about the subject this way, I didnt even know it was a Hx... Any suggestions about some good threads to read up on as to the workings of a machine like this one?
                Anyway, to clarify, I bought the machine from a private sale and the machine was in a coffee shop until late last year.
                I only ran water through the group and didnt notice a stink, although my sense of smell is pretty bad, so Ill have to check again. When you say water from the boiler does that mean straight from the water spout?
                Ill be firing it up on the weekend and having a play (extra long weekend for me) so Ill no doubt find some more problems to add to the list.

                Cheers for the help,


                • #9
                  Re: Descaling Boema 2 Goup



                  boiler water will come out of the hot water ("tea") spout.....

                  so as FC said- run some water from the groups into a nice white porcelain cup and check the colour and smell (use someone elses nose ;D)...

                  Then get the trained nose to sniff the steam - but not too close!

                  Then run some water out of the hot water spout into the cup and again check colour and smell...

                  And let us know what you find.

                  If you do a google search on "HX coffee" you will find plenty of sites with "how they work" type info.... and there are quite a few threads here.... search for 2 group commercial.

                  Good luck.


                  • #10
                    Re: Descaling Boema 2 Goup

                    Milk suck-back is one of the things that scares me from using that auction site if there is no chance of an inspection beforehand.

                    If I had a contaminated boiler Id probably resort to extreme methods like caustic soda soaks or even a base bath (caustic sode dissolved in alcohol). Theres not much organic matter that can survive that.

                    Either bead or sand blasting would be another option.....


                    • #11
                      Re: Descaling Boema 2 Goup

                      My workshop also gets into "extreme methods" as you described Sparky so believe you me, when we condemn something as not worth going on with, its condemned hehe! Unfortunately it also means weve already spent some hours on someones machine, unsuccessfully (and remember this will usually be tied to time / money constraints as well as severity of contamination),  and were not going to get paid for it......

                      For people who are inexperienced with this stuff however I think its better for them to try a "proprietary" solution specifically formulated for the comes in a bottle, doesnt need mixing, they follow the know what I mean. Easier, and safer for them, and safer for us in case we suggest something, and someone gets hurt trying it!



                      • #12
                        Re: Descaling Boema 2 Goup

                        Ok, I checked the water from the boiler and its clean,clear and doesnt stink, the steam is good as well.  The only blue water is coming from the groups and it doesnt stink as far as I can detect.

                        Ill attach some photos.
                        This one is the colour of the water (its actually greener than what shows on my monitor)


                        • #13
                          Re: Descaling Boema 2 Goup

                          And this is the grit I found in the bottom


                          • #14
                            Re: Descaling Boema 2 Goup

                            Pretty colour. Not sure that Id want it in my coffee, but its pretty.

                            Hopefully someone can help you with it.


                            • #15
                              Re: Descaling Boema 2 Goup


                              That is really weird!

                              Water stays in the boiler for a long time and is very slowly replaced.... with only pure water(as steam) leaving most of the time.... contamination therefore remains for a very long time.

                              But the water from the groups is fresh each time.... and the colour indicates something is attacking the copper and or brass in that path.... the water has a typical dissolved copper salt colour..... but what? And whatever it is- it must be attacking it pretty fast or it would have been flushed out by the passage of fresh water each time.....

                              Im at a loss to figure out what it could be.... I had assumed some sort of boiler contamination- but contamination of the brew water alone - as I said, that is weird!

                              Anyone any ideas?