Results 1 to 15 of 15

Thread: BZ99 Steam out of group head and drip tray filling....

  1. #1
    Senior Member
    Join Date
    Nov 2010
    Location
    Adelaide
    Posts
    364

    BZ99 Steam out of group head and drip tray filling....

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hi all,

    Loving my new (used) BZ99 but it has developed an odd condition. I dosed and tamped some coffee into the group handle, locked it in place and hit the brew button and nothing came out. Even for a tight extraction I usually get at least some coffee. I removed the group handle and pressed the brew switch again and all I got was steam. The pump was running but didnt sound as if it was under load. I also noticed that the drip tray was filling up slowly too.

    The next thing I did was to put some chemical in and backflush a few times just to try and clean any gunk out. Probably 8 out of the 10 times the machine behaved normally building pressure and I could see the group handle move slightly indicating this. On stopping the brewing cycle it mostly hissed water into the drip dray as per normal. The other 2 occasions the pump was running, although not under load, no pressure appeared to build in the group handle and the drip tray slowly filled with water.

    Another observation is that while pulling a shot occasionally the drip tray slowly fills with water. Correct me if Im wrong but thats not supposed to happen is it?

    Can anyone identify what the problem is?

    Thanks in advance.

  2. #2
    Site Sponsor coffee_machinist's Avatar
    Join Date
    Jun 2011
    Posts
    683

    Re: BZ99 Steam out of group head and drip tray filling....

    Sounds to me like there is a problem with the group solenoid valve if the drip tray is filling during a brew cycle. If it is intermittent, the solenoid coil is probably OK but the plunger might be sticking inside the valve body, gummed up with coffee or scale?

  3. #3
    Senior Member
    Join Date
    Nov 2010
    Location
    Adelaide
    Posts
    364

    Re: BZ99 Steam out of group head and drip tray filling....

    Thanks very much Rick,

    Your suggestion seems to explain the drip tray filling while brewing - cheers. Is the group head occasionally producing steam only likely to be caused by the same thing or are they most likely different causes?
    Is the solenoid valve the sort of thing that you take out and clean or just replace? I have only just acquired the machine and it is 15 years old but appears to have had little use and mostly is in excellent condition. See http://coffeesnobs.com.au/YaBB.pl?num=1309702819 for photos.

    Attached is now some images of the solenoid valve.



  4. #4
    Site Sponsor
    Join Date
    Aug 2006
    Posts
    929

    Re: BZ99 Steam out of group head and drip tray filling....

    Pretzal;

    Yes, machine looks very clean however 15 years are 15 years. From picture I can see there is original pump, pressure switch and probably solenoid. The anti vacuum valve is been change. the best way to do this is by start from the end to the beginning.

    1. Undo shower screen and clean group head
    2. Undo group head (you need Allen keys)Check if the 4 holes are clean
    3. Take the pipe from the group head to the solenoid and check if is clean
    4. Undo solenoid and give it a clean or replace. When you are there clean restricter from solenoid to Heat Exchanger
    5. Clean pipe from solenoid to Heat Exchanger.

    If all the as above do not fix the problem, it probably is your Heat Exchanger is block, you need a new one is about 100 dollars

    Any questions happy to help.
    Ps. enclose diagrams
    http://bezzeracoffeemachine.com.au/images/diagrams/bz99_diagram.pdf


    Regards


    Renzo
    Di Bartoli Home Barista Centre

  5. #5
    Senior Member
    Join Date
    Nov 2010
    Location
    Adelaide
    Posts
    364

    Re: BZ99 Steam out of group head and drip tray filling....

    Wow,

    Thanks Renzo for the detailed post.

    Before I dive in I have a couple of comments/questions if I may....

    Firstly thanks, I changed the anti-vacuum valve on your suggestion.

    Before I start pulling things apart do I need to order a host of seals/o-rings, spacers etc? If that is the case then I should probably contact Bezzera and get them to supply me these parts (or alternatively yourself if you do supply them?) before I start disassembly.

    Secondly do you recommend any cleaning product to clean the pipes/solenoid or just a bit of hot water, detergent and a good scrub? Would cafetto/hot water do the job?

    Thanks once again,

    Pretzal

  6. #6
    Site Sponsor
    Join Date
    Aug 2006
    Posts
    929

    Re: BZ99 Steam out of group head and drip tray filling....

    yes, but to clean the copper pipes I found that you descale does a better job

    http://www.dibartoli.com.au/product/Clean_Machine_Solution_250ml_-_Descaler

    What parts do you need?

    Regards

    Renzo
    Di Bartilo Home Barista Centre

  7. #7
    Senior Member
    Join Date
    Nov 2010
    Location
    Adelaide
    Posts
    364

    Re: BZ99 Steam out of group head and drip tray filling....

    Thanks Renzo,

    I was hoping to keep using the machine and get all the parts together before I started fixing it, however the machine just fills up the drip tray now more frequently so I will descale the copper pipes and clean the solenoid tonight per your instructions and see what parts are required.

  8. #8
    Senior Member
    Join Date
    Nov 2010
    Location
    Adelaide
    Posts
    364

    Re: BZ99 Steam out of group head and drip tray filling....

    Well I took it all apart and soaked it overnight in cafetto restore and put it back together. It looks all shiny and a little pink but unfortunately it still leaks into the drip tray when I put in the blind filter and pressed the brew button - so I guess Im up for a new solenoid?

    thanks in advance

  9. #9
    Senior Member
    Join Date
    Nov 2010
    Location
    Adelaide
    Posts
    364

    Re: BZ99 Steam out of group head and drip tray filling....

    Seeing as I had nothing to lose with the solenoid I completely disassembled it and cleaned it just to rule out perhaps some crud preventing it from functioning properly. Here is the picture after cleaning -



    Looks pretty clean to me. Is it possible that not all of the solenoid needs replacing? Ill put it all back together tonight and try again. Maybe the heat exchanger is blocked as Renzo suggested...

  10. #10
    Site Sponsor
    Join Date
    Aug 2006
    Posts
    929

    Re: BZ99 Steam out of group head and drip tray filling....

    Could be the coil, the one which has fail. Put it back and see if works.

    Good luck

    Regards

    Renzo
    Di Bartoli Home Barista Centre

  11. #11
    Senior Member
    Join Date
    Nov 2010
    Location
    Adelaide
    Posts
    364

    Re: BZ99 Steam out of group head and drip tray filling....

    I put it back together and unfortunately it still leaks into the tray :-[. I reckon it might be time to get it serviced professionally. Sincerely thanks for the help. Ill post back with results...

  12. #12
    Senior Member
    Join Date
    Nov 2010
    Location
    Adelaide
    Posts
    364

    Re: BZ99 Steam out of group head and drip tray filling....

    Thought I would update this thread since its been a little while.

    I took the machine back to the repair shop and after 2 weeks she came back - no new parts but appeared to be working.....for 3 days....then at 5am in the morning as Im brewing a much needed shot before work...poof! and Im standing in total darkness. I trundled outside and reset the power only to have it trip again. Third time I turned off the machine before resetting the power with no further tripping. Least that confirmed it.

    I then took the machine later that day to a different repair shop and waited another 2 weeks for it to be returned to me with a replaced group solenoid valve.

    A week or so on it doesnt seem to miss a beat which is great. The by now 2 week old home roasted Peru ceja de selva was superb! Makes me think I should allow my other roasts more time before devouring. Hopefully from now on she will live up to the lofty expectations I have for her.

    Once again thanks for the advice and tips from the other snobs especially Renzo!


  13. #13
    Site Sponsor
    Join Date
    Aug 2006
    Posts
    929

    Re: BZ99 Steam out of group head and drip tray filling....

    No mate thank you to you for consuming Peruvian beans.

    Actually I am Peruvian.

    Always happy to help.

    Regards

    Renzo
    Di Bartoli Home Barista Centre

  14. #14
    Senior Member
    Join Date
    Nov 2010
    Location
    Adelaide
    Posts
    364

    Re: BZ99 Steam out of group head and drip tray filling....

    The temptation to get more Peruvian from Andy is almost overwhelming! Peruvian, along with Guatemalan, are definitely on my list of beans to sample a lot more of!

  15. #15
    Super Moderator Javaphile's Avatar
    Join Date
    Dec 2004
    Location
    Earth!
    Posts
    15,570

    Re: BZ99 Steam out of group head and drip tray filling....

    [split] [link=http://coffeesnobs.com.au/YaBB.pl?num=1315640473/0#0][splithere][/link][splithere_end]



Similar Threads

  1. Rancilio Silvia V3 - Steam from group head - need help!
    By rnm1985 in forum Brewing Equipment - Midrange ($500-$1500)
    Replies: 8
    Last Post: 20th December 2011, 12:26 PM
  2. Nemox Fenice: Steam from group head
    By danga_03 in forum Brewing Equipment - Midrange ($500-$1500)
    Replies: 14
    Last Post: 25th October 2011, 07:12 PM
  3. Silvia drip tray
    By pszilard in forum Brewing Equipment (non-machine specific)
    Replies: 3
    Last Post: 12th January 2007, 10:38 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •