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Date: 29 Dec 2006 15:52:31
From: eric.jobe@gmail.com
Subject: La Marzocco Linea Problem
Hi folks:

I'm at my local indy coffee shop, and their two-group La zocco Linea
is acting strange. At idle, fully warmed up, the pressure reads 12
bars. When a shot is pulled or water run through the group, the
pressure falls to 5.5 bars. After it is turned off, the pressure
returns to 12 bars. Any idea what is going on. It would be nice for
business if we could find the problem before the maintenance guy comes
tomorrow.

-Eric





 
Date: 29 Dec 2006 21:56:34
From: eric.jobe@gmail.com
Subject: Re: La Marzocco Linea Problem
Thanks so much for the help. I will share this with the owner ASAP



 
Date: 29 Dec 2006 20:34:23
From: Paul Pratt
Subject: Re: La Marzocco Linea Problem

Barry Jarrett wrote:
> On Fri, 29 Dec 2006 19:31:17 -0500, sprsso <acritzer@cfl.rr.com>
> wrote:
>
> >At first read, I'd guess the manometer was bad or weakening. Had 2 of
> >those this week. What does it read when the machine is cold? Has
> >anyone tried a pump adjustment?....al
> >
>
> the zoccos read the pressure at the brew boiler, not at the pump.
> the 5 bar reading sounds like the pump pressure needs to be adjusted.
> the 12 bar at idle, or after a shot, is NORMAL for a linea.

That catches a lot of people out and causes a lot of undue call-out
hassle for people who used to have HX machines and now see an
alarmingly high static pressure.



 
Date: 29 Dec 2006 18:51:25
From: Mldhab
Subject: Re: La Marzocco Linea Problem
Barry has it right. Gospel. The expansion valve in the drain cup is
normally adjusted to 11.5 - 12 Bar. If the Check valve in the water
line feeding the brew boiler is 'good' the pressure will slowly rise on
the brew boiler gauge to what the expansion valve is set at, after
pulling a shot. The pressure rises because of the expansion of the
fresh shot (or two) of cold water as it heats, that was pumped into the
brew boiler while pulling the shot. The brew pressure during the pull
will be whatever the bypass valve on the pump is set at. If you see
water mains pressure at the brew boiler between shots....youve got a
bad check valve. If you can't adjust the brew pressure (during the
pull) up to an acceptable pressure, by adjusting the bypass valve at
the pump........you've either a bad bypass valve/spring etc. or a worn
out pump. Righty - Tighty, on the adjustment will raise the brew
pressure.

Mike



 
Date: 29 Dec 2006 16:51:21
From: eric.jobe@gmail.com
Subject: Re: La Marzocco Linea Problem


On Dec 29, 6:48 pm, "Craig Andrews" <alt.cof...@deletethis.rogers.com >
wrote:
> <eric.j...@gmail.com> wrote in messagenews:1167439448.361753.43550@v33g2000cwv.googlegroups.com...
>
>
>
> > sprsso wrote:
> >> At first read, I'd guess the manometer was bad or weakening. Had 2 of
> >> those this week. What does it read when the machine is cold? Has
> >> anyone tried a pump adjustment?....al
>
> > What is a manometer?http://dictionary.reference.com/browse/Manometer
> Craig.

Well, that's obvious. But where is this manometer? Is it the same
pressure gauge on the front of the machine, or elsewhere?



  
Date: 29 Dec 2006 20:44:55
From: sprsso
Subject: Re: La Marzocco Linea Problem
Sorry. I should have been more specific. I was referring to the pump
pressure guage on the front of the machine. There are several things
that can cause readings of the nature you describe, not the best of
which is a failure of the expansion valve or the check valve. Under
normal conditions in most machines, this guage reads realtime pump
pressure during extraction, refill and cleaning functions. The reading
under no load is usually ambient line pressure. The first things I
would check in the field, given that the readings are both on the high
and low sides, would be adjustability of the pump, temps of the pump
and flowmeters to assure no hot water backflow into the cold water
system, and abnormal expulsion into the drip tray. Calcium buildup
inside the guage is something else to check.
I would still guess the manometer....al


On 29 Dec 2006 16:51:21 -0800, "eric.jobe@gmail.com"
<eric.jobe@gmail.com > wrote:

>
>
>On Dec 29, 6:48 pm, "Craig Andrews" <alt.cof...@deletethis.rogers.com>
>wrote:
>> <eric.j...@gmail.com> wrote in messagenews:1167439448.361753.43550@v33g2000cwv.googlegroups.com...
>>
>>
>>
>> > sprsso wrote:
>> >> At first read, I'd guess the manometer was bad or weakening. Had 2 of
>> >> those this week. What does it read when the machine is cold? Has
>> >> anyone tried a pump adjustment?....al
>>
>> > What is a manometer?http://dictionary.reference.com/browse/Manometer
>> Craig.
>
>Well, that's obvious. But where is this manometer? Is it the same
>pressure gauge on the front of the machine, or elsewhere?



   
Date: 30 Dec 2006 01:58:26
From: Barry Jarrett
Subject: Re: La Marzocco Linea Problem
On Fri, 29 Dec 2006 20:44:55 -0500, sprsso <acritzer@cfl.rr.com >
wrote:

>and flowmeters to assure no hot water backflow into the cold water
>system,

linea flowmeters are in the hot water system.




  
Date: 29 Dec 2006 19:58:21
From: Craig Andrews
Subject: Re: La Marzocco Linea Problem

<eric.jobe@gmail.com > wrote in message
news:1167439881.204674.18610@n51g2000cwc.googlegroups.com...
>
>
> On Dec 29, 6:48 pm, "Craig Andrews" <alt.cof...@deletethis.rogers.com>
> wrote:
>> <eric.j...@gmail.com> wrote in
>> messagenews:1167439448.361753.43550@v33g2000cwv.googlegroups.com...
>>
>>
>>
>> > sprsso wrote:
>> >> At first read, I'd guess the manometer was bad or weakening. Had 2
>> >> of
>> >> those this week. What does it read when the machine is cold? Has
>> >> anyone tried a pump adjustment?....al
>>
>> > What is a
>> > manometer?http://dictionary.reference.com/browse/Manometer
>> Craig.
>
> Well, that's obvious. But where is this manometer? Is it the same
> pressure gauge on the front of the machine, or elsewhere?
>

Obvious?, ok.., you asked though... {:-


 
Date: 29 Dec 2006 16:44:08
From: eric.jobe@gmail.com
Subject: Re: La Marzocco Linea Problem

sprsso wrote:
> At first read, I'd guess the manometer was bad or weakening. Had 2 of
> those this week. What does it read when the machine is cold? Has
> anyone tried a pump adjustment?....al


What is a manometer?



  
Date: 29 Dec 2006 19:48:24
From: Craig Andrews
Subject: Re: La Marzocco Linea Problem

<eric.jobe@gmail.com > wrote in message
news:1167439448.361753.43550@v33g2000cwv.googlegroups.com...
>
> sprsso wrote:
>> At first read, I'd guess the manometer was bad or weakening. Had 2 of
>> those this week. What does it read when the machine is cold? Has
>> anyone tried a pump adjustment?....al
>
>
> What is a manometer?
>

http://dictionary.reference.com/browse/Manometer
Craig.



 
Date: 29 Dec 2006 19:31:17
From: sprsso
Subject: Re: La Marzocco Linea Problem
At first read, I'd guess the manometer was bad or weakening. Had 2 of
those this week. What does it read when the machine is cold? Has
anyone tried a pump adjustment?....al



On 29 Dec 2006 15:52:31 -0800, "eric.jobe@gmail.com"
<eric.jobe@gmail.com > wrote:

>Hi folks:
>
>I'm at my local indy coffee shop, and their two-group La zocco Linea
>is acting strange. At idle, fully warmed up, the pressure reads 12
>bars. When a shot is pulled or water run through the group, the
>pressure falls to 5.5 bars. After it is turned off, the pressure
>returns to 12 bars. Any idea what is going on. It would be nice for
>business if we could find the problem before the maintenance guy comes
>tomorrow.
>
>-Eric



  
Date: 30 Dec 2006 01:55:40
From: Barry Jarrett
Subject: Re: La Marzocco Linea Problem
On Fri, 29 Dec 2006 19:31:17 -0500, sprsso <acritzer@cfl.rr.com >
wrote:

>At first read, I'd guess the manometer was bad or weakening. Had 2 of
>those this week. What does it read when the machine is cold? Has
>anyone tried a pump adjustment?....al
>

the zoccos read the pressure at the brew boiler, not at the pump.
the 5 bar reading sounds like the pump pressure needs to be adjusted.
the 12 bar at idle, or after a shot, is NORMAL for a linea.



   
Date: 30 Dec 2006 18:09:21
From: sprsso
Subject: Re: La Marzocco Linea Problem
That's interesting. Learn something new every day. Not many in my
ket, but I do know one I can play with nearby. In my spare
time....al


On Sat, 30 Dec 2006 01:55:40 GMT, Barry Jarrett
<barry@rileys-coffee.com > wrote:

>On Fri, 29 Dec 2006 19:31:17 -0500, sprsso <acritzer@cfl.rr.com>
>wrote:
>
> >At first read, I'd guess the manometer was bad or weakening. Had 2 of
> >those this week. What does it read when the machine is cold? Has
> >anyone tried a pump adjustment?....al
> >
>
>the zoccos read the pressure at the brew boiler, not at the pump.
>the 5 bar reading sounds like the pump pressure needs to be adjusted.
>the 12 bar at idle, or after a shot, is NORMAL for a linea.



    
Date: 31 Dec 2006 03:02:54
From: Barry Jarrett
Subject: Re: La Marzocco Linea Problem
On Sat, 30 Dec 2006 18:09:21 -0500, sprsso <acritzer@cfl.rr.com >
wrote:

>That's interesting. Learn something new every day. Not many in my
>ket, but I do know one I can play with nearby. In my spare
>time....al
>
>

in your copious spare time, eh? ;(

it's always fun to look under the hood when you get a chance.