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Thread: BZ10 owners - request for information on steaming performance

  1. #1
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    BZ10 owners - request for information on steaming performance

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hi fellow BZ10ers

    I've had a BZ10 for 1.5 years now, and really happy with it. Though lately I'm suspecting my machine is going downhill in terms of steam performance, which is supposed to be a strength of this model. Steam supply starts out strong, but the machine loses pressure head pretty quickly.

    Now I'm wondering if I'm imagining things, or if the machine has always performed this way.

    Steaming into a jug of water, the pressure head starts at 1.4. At 10 seconds it is reduced to 1.0. At 15 seconds it is 0.9. At 30 seconds it is 0.8. If steaming while pulling a shot, I've had the pressure drop to as low as 0.5, which I think is inadequate.

    Next time you've got your machine running, could I kindly request another owner to report how quickly you're losing pressure head when steaming? Thanks in advance!

    (I could probably retain pressure by swapping to a single-hole tip, but that might just be masking some underlying problem with the heating element etc.)
    Last edited by rustyfence; 4 Weeks Ago at 08:54 PM.

  2. #2
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    I've got a BZ07 and seeing similar performance to you (yet with a delta as my machines set point is around 1.0). If definitely seems to be lacking some performance it once had.

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    Thanks for the data point chocdog. As far as I understand the guts of the machines are essentially identical.

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    Actually this happened to me this morning, I just had the BZ10 over a week.

    I noticed the drop occurred just as i stopped my shot and the 3 way valve opened (while steaming milk). My guess is the vacuum break valve opened to stop back block, causing the pressure drop. Not entirely sure. I'll keep monitoring.

    This also seem to be consistent with air entering into the boiler, if it is, not sure how to reprime the boiler (perhaps letting steam valve run open ?)

    Any inputs would be great

  5. #5
    Senior Member robusto's Avatar
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    By the time a vacuum break valve opens, pressure in the boiler would be pretty near zero. There needs to be pressure to keep the valve piston up.

    For this condition to occur, there would not have been any steam pressure available for steaming milk for maybe several minutes beforehand rather than right away.

    I'm kinda guessing here that the vacuum break valve is faulty -- stuck CLOSED at all times. (If it is stuck open you'd hear the constant hissing, so I'm discounting that scenario)

    This would mean that after the machine is turned on, air inside the boiler is being compressed instead of being expelled.

    The pressurestat being dumb, doesn't know the difference between steam pressure and air pressure, so it turns off the heating element when it senses 1 bar or whatever it is set to.

    When you go to steam milk, out comes the compressed air...and that's all. Hot air, but no steam.

    How to test if that's the case?

    With the machine cold, push down on the vacuum break valve piston. If it goes down, it was stuck shut. It should be down already.

    Alternatively, with the machine hot, open the steam valve to expel the compressed air. Close it. Wait a minute, then try steaming milk and see whether that's worked.
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    Quote Originally Posted by robusto View Post
    By the time a vacuum break valve opens, pressure in the boiler would be pretty near zero. There needs to be pressure to keep the valve piston up.

    For this condition to occur, there would not have been any steam pressure available for steaming milk for maybe several minutes beforehand rather than right away.

    I'm kinda guessing here that the vacuum break valve is faulty -- stuck CLOSED at all times. (If it is stuck open you'd hear the constant hissing, so I'm discounting that scenario)

    This would mean that after the machine is turned on, air inside the boiler is being compressed instead of being expelled.

    The pressurestat being dumb, doesn't know the difference between steam pressure and air pressure, so it turns off the heating element when it senses 1 bar or whatever it is set to.

    When you go to steam milk, out comes the compressed air...and that's all. Hot air, but no steam.

    How to test if that's the case?

    With the machine cold, push down on the vacuum break valve piston. If it goes down, it was stuck shut. It should be down already.

    Alternatively, with the machine hot, open the steam valve to expel the compressed air. Close it. Wait a minute, then try steaming milk and see whether that's worked.
    I'll see if i can check the vac break valve, the BZ10 uses a pressure stat/vac break/pressure relief.

    I'll see if the exploded diagram can actually show if the valve is testable at this point.

    *** Edit = Any chance the boiler fill solenoid popped open when brewing? I take the control board should have been wired/programmed to prevent this, but is there such an opportunity for that to occur if there isn't an interlock in place?
    Last edited by 392392; 3 Weeks Ago at 03:13 PM.

  7. #7
    Senior Member noidle22's Avatar
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    From what I can see, the BZ10 uses the same wand/tip as my Matrix. I have never quite been happy with the steam performance of my Matrix and it's a dual boiler.
    Even with the boiler temp set to 130C, the steam starts out strong but drops to 1 bar or just below by the last third of frothing. By this time, the milk is squealing and is difficult to control the texture. I've tried many types of milk , some handle it better than others but mostly it's not very good.

    I've just installed a Breville Dual Boiler wand onto the machine. The tip uses three very small holes. Now, the steam pressure remains at 1.5 bar for the duration of steaming and it is very easy to control. It is slower than the original wand but only by about 30%. I also lost the cool touch function but I think it's a bit of a gimmick anyway. The wand has a rubber sleeve on it for handling so it doesn't matter if it gets hot.

    As the BZ10 has even less boiler pressure, the issue with the tip would be even worse I could imagine. As Bezzera use fairly unusual tips on the wand, changing the whole wand is the easiest option I think. You could try getting a different tip with smaller holes, or even just blocking one of the holes to see how that goes.
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  8. #8
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    So I just tried the toothpick trick and blocked one of the two holes on the stock tip. The machine had no problem maintaining 1 bar in this config. Also the microfoam was way better.

    Still disappointed/scratching my head over why the machine isn't grunty enough to maintain pressure with the two-hole tip. Heating element on the way out, perhaps?

    Or maybe a de-calc is in order? I have the gear to descale but never been game to try - the manufacturer doesn't recommend.

    Now to scour the interwebs for a compatible single hole tip (or wand) ...

    [Edit: another thread mentions the Silvia 1-hole as compatible, will give it a go]

    [Edit: did the descale, got slightly better performance - takes longer for the pressure to drop to 0.8 bar during solo steaming with two holes. As an aside, the descale did temporarily cause a blockage in the OPV flow bank to the tank and stalled the pump when using a blind basket - seems to be cleared now though, whew.]
    Last edited by rustyfence; 2 Weeks Ago at 02:42 PM.

  9. #9
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    My Bezzera BZ07 original steam tip was 2x1.5mm holes with 8mm male thread. And I assume the BZ10 is the same. I ended up buying a 2 x 1.2mm steam tip from JetBlack Espresso. This improved things.

    The hyperlink I had is no longer working but I am sure you’ll find it on their site.
    392392 likes this.

  10. #10
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    Steaming around 400ml of milk while pulling an 18g shot this morning, takes about, 20-30 seconds to finish steaming that amount of milk (really fast..)

    Dropped boiler pressure from 1.3 bar to 0.7; i can get decent microfoam, but its still abit courser than i'd like..




    Quote Originally Posted by chocdog View Post
    My Bezzera BZ07 original steam tip was 2x1.5mm holes with 8mm male thread. And I assume the BZ10 is the same. I ended up buying a 2 x 1.2mm steam tip from JetBlack Espresso. This improved things.

    The hyperlink I had is no longer working but I am sure you’ll find it on their site.
    Was it a significant improvement?
    Juggling between a single hole Silvia tip, or as you recommended...

  11. #11
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    I think it was. But it was a few years ago now!

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    So, I got greedy and have ordered both now. I'll report back once they arrive ...

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    OK, so the Jet Black Espresso 10mm female tip with 2 x 1.2mm holes ... does not fit the BZ10

    The thread on the tip is coarser than the thread on the wand arm.

    So I have no use for this now, if someone wants it ....

  14. #14
    Senior Member robusto's Avatar
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    Rusty, if you feel one hole would fix your problem it's an easy matter to solder one shut with lead-free solder.

    I did that recently to 2 of the 4 holes on my Grimac where I have the opposite problem of too much steam too quickly.

    If you go down this path, decide first which hole points in the direction you are comfortable steaming.
    Dimal likes this.

  15. #15
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    Quote Originally Posted by rustyfence View Post
    OK, so the Jet Black Espresso 10mm female tip with 2 x 1.2mm holes ... does not fit the BZ10

    The thread on the tip is coarser than the thread on the wand arm.

    So I have no use for this now, if someone wants it ....
    I thought you would need an 8mm male thread?
    My steam tip is 8mm/M

    hmm

  16. #16
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    Bezzera (for some odd reason) choose to use a non-standard thread for this.
    Makes things more difficult than it needs to be...

    Mal.
    Last edited by Dimal; 1 Week Ago at 03:55 PM.

  17. #17
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    There are several metric standard threads: the one designated with an M (eg M10) is usually ISO Metric Coarse (eg 10mm major diameter x 1.5mm thread pitch).

    ISO Metric Fine and Extra fine (both usually designated MF) have, logically, smaller thread pitches. For 10mm the common one is 1.0 mm pitch (used for bicyle derailleur mounts and for spark plugs) but 0.75mm and 1.25mm also exist.

    You want a non-standard thread? Mavic decided to use 12mm x 1mm double lead (eg pitch = 1mm but lead = 2mm) on their through axle system. Try buying a tap for that off the shelf.
    Dimal and robusto like this.

  18. #18
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    To be honest I've never noticed the issue with the steam pressures only if im doing a really big jug.
    It's literally in the shop for a service right now, but i'll report back when i've got in back on the bench.

    I'm running the stock tip and seems to be humming along okay.

  19. #19
    Senior Member CafeLotta's Avatar
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    Quote Originally Posted by rustyfence View Post
    Still disappointed/scratching my head over why the machine isn't grunty enough to maintain pressure with the two-hole tip. Heating element on the way out, perhaps?

    Or maybe a de-calc is in order? I have the gear to descale but never been game to try - the manufacturer doesn't recommend.
    You could always get in contact with the Australian Distributor Barazi Bezzera Coffee Machines and discuss your concerns. They seem to be very good at addressing Bezzera owners queries.
    Dimal likes this.

  20. #20
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    On my Bezzera (Domus Galatea, 2L HX), the steam is very 'blasty.' It starts at 1.35 and goes down to ~1 straight away. Usually the steaming happens very quickly and is done before it goes much lower than that. One thing I notice is it 'recovers' to 1.35 almost instantly when I turn the steam off. If anything the issue I have is 'wet' steam. I've wondered recently if there might be an advantage in lowering the water level slightly.

    I'm not sure what the thread is like on the BZ10 arm, but I had some joy with the Profitec tips that Jet Black espresso sell. If I use the Prof fine two-hole it maintains higher pressure, the only thing is I had to take out the non-burn tubing on the Bezzera arm, because the Profitec tip is slimmer on the inside. If you decide to buy a different tip to the default one I would be wary of the seal around the non burn tubing if yours has that.
    Last edited by liberdade; 4 Days Ago at 11:18 PM.

  21. #21
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    Does anyone know whats the largest basket you can fit into the portafilter ?

    I guess maybe owners just list the largest basket they use? (bottomless doesnt count)

  22. #22
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    Quote Originally Posted by 392392 View Post
    Does anyone know whats the largest basket you can fit into the portafilter ?

    I guess maybe owners just list the largest basket they use? (bottomless doesnt count)
    I'm not sure if its the largest - but ive got a 22g Pesado basket since i've had the machine.
    392392 likes this.



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