Adjusting brew temperature of Vibiemme Double Boiler Junior

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janweel

Postby janweel » Dec 11, 2009, 5:37 am

I recently bought a vibiemme domobar junior (double boiler). It's a fantastic machine. I made the best espresso ever with this machine and my home roasted beans. There is only one problem. The temperature of the brewing boiler seems to be too high. A lot of steam is coming out of the the group head, also after a long cooling flush (about 60 seconds). That makes the coffee too hot to drink and it destroys the crema. When the machine is on for a short term i'm able to make a perfect cup. But when it's on for a longer time it gets too hot. I've played with:

* The maximum pressure: is now 9 bar
* Pressure of steam boiler: is now between 0.9 and 1.1
* Temperature of the brewing boiler. Whatever i do, there seems to be no difference in coffee temperature. There's still a lot of steam. I also changed the temperature when the machine is off.

Could there be an issue with the pressurestat of the brewing boiler, or the temperature/ pressure sensor of the brewing boiler? What could be the issue? What could be done to fix this problem? Does anyone have a more complete manual than the standard one in english or italian? Any idea's? I also mailed this question to vibiemme Italy. I got no reply ... that's a crying shame :(

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erics

Postby erics » Dec 11, 2009, 7:32 am

There is a temperature adjustment knob for the brew boiler located as shown below:
Image
I believe that turning the knob counter-clockwise reduces the brew boiler temperature setting - it has been a while. Turn it in small increments - say 1/8 turn - and give the grouphead about 15-20 minutes to cool down a bit before you brew. A ~2 second flush is all that is needed prior to brewing.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at erols dot com

janweel

Postby janweel » Dec 11, 2009, 9:57 am

thanks eric, unfortunately that does not seem to work. i've tried that, i even shut the machine off before adjusting. when i adjust that knob too much counter clockwise the brewing boiler even seems to stop heating. and the machine will give me a cold espresso. :-( anyone, any ideas?

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stefano65
Sponsor

Postby stefano65 » Dec 11, 2009, 10:42 am

the Prodigy thermostat that vbm uses are with a range between 70-120 c
the adjustment knob is pretty sensitive one millimeter or so will make a difference
if you go too far you will hear it click and there for you will go below the temp of that moment

however going down in temp
you will need to wait for the machine to stabilize the temp
( cool down flushing)
before deciding the temp setting
Stefano Cremonesi
Stefano's Espresso Care
Repair & sales from Oregon.

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erics

Postby erics » Dec 11, 2009, 12:39 pm

Turn it in small increments - say 1/8 turn . . .

. . . is pretty sensitive one millimeter or so will make a difference

OR, as a long ago US TV commercial said, "a little dab il do ya"
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at erols dot com

janweel

Postby janweel » Dec 12, 2009, 11:56 pm

Thanks for your reply's Stefano and Eric! Maybe a made to large adjustments to the temperature knob. I'll let you know if it is working after the tiny adjustment. I'll test it as soon i am back in my country.

Now i'm on holiday in Vietnam. I drink here a lot of Vietnamese coffee. That's quite strong and good stuff. Very different from a regular espresso though. I don't know how they roast that stuff. Maybe i'll start a thread about that! Keep on cupping! :-)

janweel

Postby janweel » Jan 10, 2010, 4:37 am

Unfortunately the lowest temperature setting still gives me a lot of steam (it's cooking!). :( I suspect that thermostat (Prodigy TR/86) is broken. I checked the electrical wire connections and they seem to be fine. I read somewhere that these types of thermostats often have problems.

Does anyone recognise this problem (eric, stefano)? Could the thermostat be the cause of the problem? http://www.chriscoffee.com/products/hom...thermostat Sell's replacements for the Prodigy TR/86. But unfortunately he does not seems to deliver to the Netherlands (where i live). Does anyone know where to get this thermostat in the Netherlands or from another supplier on the internet?

Many Thanks!!!

Jan van der Weel
Netherlands

P.S. i just come back from a long vacation. Had no good coffee in 2 months! Dying for a good cup! :D

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erics

Postby erics » Jan 10, 2010, 9:59 am

Firstly, I would NOT count on those thermostats being similar other than the fact that the manufacturer happens to be the same. Secondly, since this is the case -
I recently bought a vibiemme domobar junior (double boiler).

why not contact the place of purchase? :) Is the machine still under some sort of warranty?
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at erols dot com

janweel

Postby janweel » Jan 10, 2010, 1:55 pm

Thanks Eric. You are right. The machine still has warranty :D

The problem is however that the machine was bought in Italy (my girlfriends family bought it there for me, they are Italians). It is very difficult to communicate with the Italian shop because their English is very bad (they just don't speak English). Also it would take a long time (and costs) to send the machine back and forth to Italy. In this case i think that's not a very practical solution. I think that a broken thermostat should be quite easy to fix. But i'm not 100% sure about that. :?:

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erics

Postby erics » Jan 10, 2010, 5:39 pm

OK, I understand the language difficulties and certainly understand the machine transportation issues. Why not, at least, send those guys an email describing the problem and inquire as to whether they have an "authorized" repair facility near you. For sure Vibiemme machines are sold in the Netherlands and you could also approach them as regards in-warranty repair of a machine purchased elsewhere - could be a difficult situation.

But before this, turn the thermostat all the way down (fully counter-clockwise I BELIEVE) and let the machine be at idle for at least an hour. You should, most definitely, NOT get any steam at this setting. Now turn the thermostat all the way up (fully clockwise) and let the machine rest for another hour or so. See if you can discern any difference between the two events.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at erols dot com