Hi guys:

Just wanted to get a little advice from the "mechanics" on the board.

First the background FWIW:

I purchased a Cimbali Junior a month or so ago and initially all was bliss. I became intrigued with the Scace thermofilter after following the thread here and purchased one a few weeks ago.

At that point "target fixation" on my Fluke meter set it and I was driving myself crazy with temp readings that were progressively becoming cooler despite my attention to technique. I fully agreed with Malachi's statement in his 'Truth or Lies' post that E61's don't "run cool" but here in front of me seemed to be a clear contradiction.

I'm very tall so I don't see the pressure gauge well when I'm standing in front of Junior (you guys know what's coming!). I pulled up a chair and sat down to think things through and glanced up at the pressure gauge which read 0.5 BAR. My first thought was 'OK, I've overcooled Junior and he'll be ticked at me for the next 5 or 10 minutes'. After several moments I realized that the boiler was not kicking in to warm things up and my gauge reading was just sitting there at 0.5 BAR. I opened the tap and drew down the water level which then engaged the pump. Pressure dropped to 0.4 BAR before my boiler did activate and then heated way up into the red part of the scale (about 1.6 BAR) before shutting off. Hmmm... (when new a month or so ago Junior cycled happily between 0.8 BAR and 1.3 BAR)

The folks at Chris (who've been really great at helping me sort this out) had me try several things (not covered here in the interest of some brevity) and finally determined that my pressurestat had given up the ghost. Pretty rare thing for a Cimbali they say and they are sending me out a new one for replacement. From what I understand from talking to them as well as looking at the schematics in the owners maual, this should be a (fairly) straightforward job (I hope!).

Whew- to the point finally: Never having done this before, any "pearls" from those of you who have actually performed this switcharoo that you might offer before I begin surgery?

TIA-

Mike

k7qz wrote: I fully agreed with Malachi's statement in his 'Truth or Lies' post that E61's don't "run cool" but here in front of me seemed to be a clear contradiction.

For what it's worth... I actually said it doesn't run hot.

k7qz wrote:Whew- to the point finally: Never having done this before, any "pearls" from those of you who have actually performed this switcharoo that you might offer before I begin surgery?

Replacing the pressurestat is easy:


Cimbali Junior micro-pressurestat

Reminder: The boiler must be stone cold and the machine unplugged. Not just turned off, unplugged.

Unscrew it from the bottom coupling, move the leads over to the replacement, screw it back in. As a habit I use Teflon plumber's tape, though I'm not sure it's necessary in this case.

Malachi- Sorry for the misquote, keyboard fingers running ahead of the brain

Dan- Thanks (again!). Another case of a picture being worth a 1000 words. I "see" exactly what's to be done now. Nurse, Scalpel please...

Oh, BTW, I know each brand is a little different but while I'm there I might wish to eventually adjust the p.stat setting at some point. What incremental steps would you recommend I use on Junior's adjustment screw? (1/8th turn, 1/4 turn, 1/2 turn at a time) Just trying to understand how fine or course Cimbali's adjustments are.

-Mike

With this coupling/connection you shouldn't use teflon tape. The teflon might do that the nut isn't screwed on tight enough, so that the conical nipple/end pipe doesn't make a tight seal with the end of the union/fitting it is screwed on. And that is really what makes this connection tight.

Of course, if the nipple/end pipe isn't conical you should use teflon. But I'm pretty sure it's conical on the Junior.

Jonas wrote:With this coupling/connection you shouldn't use teflon tape. The teflon might do that the nut isn't screwed on tight enough, so that the conical nipple/end pipe doesn't make a tight seal with the end of the union/fitting it is screwed on. And that is really what makes this connection tight.

Of course, if the nipple/end pipe isn't conical you should use teflon. But I'm pretty sure it's conical on the Junior.

Mange tak Jonas-

I will look at the fitting when I replace the part.

k7qz wrote:What incremental steps would you recommend I use on Junior's adjustment screw?

It wasn't exceedingly sensitive, IIRC, with adjustments being in the 1/4 to 1/2 turn range. You will need to remove all the panels to have easy access because the side panels cover the screws holding on the back panel. When I was tweaking the pressurestat a lot, I put the side panels back in place and kept the back panel off. It's worth getting a small 7mm wrench for the adjustment instead of using pliers; Ace Hardware and Sears sell them separately.

k7qz wrote:Hi guys:

Just wanted to get a little advice from the "mechanics" on the board.

First the background FWIW:

I purchased a Cimbali Junior a month or so ago and initially all was bliss. I became intrigued with the Scace thermofilter after following the thread here and purchased one a few weeks ago.

At that point "target fixation" on my Fluke meter set it and I was driving myself crazy with temp readings that were progressively becoming cooler despite my attention to technique. I fully agreed with Malachi's statement in his 'Truth or Lies' post that E61's don't "run cool" but here in front of me seemed to be a clear contradiction.

I'm very tall so I don't see the pressure gauge well when I'm standing in front of Junior (you guys know what's coming!). I pulled up a chair and sat down to think things through and glanced up at the pressure gauge which read 0.5 BAR. My first thought was 'OK, I've overcooled Junior and he'll be ticked at me for the next 5 or 10 minutes'. After several moments I realized that the boiler was not kicking in to warm things up and my gauge reading was just sitting there at 0.5 BAR. I opened the tap and drew down the water level which then engaged the pump. Pressure dropped to 0.4 BAR before my boiler did activate and then heated way up into the red part of the scale (about 1.6 BAR) before shutting off. Hmmm... (when new a month or so ago Junior cycled happily between 0.8 BAR and 1.3 BAR)

The folks at Chris (who've been really great at helping me sort this out) had me try several things (not covered here in the interest of some brevity) and finally determined that my pressurestat had given up the ghost. Pretty rare thing for a Cimbali they say and they are sending me out a new one for replacement. From what I understand from talking to them as well as looking at the schematics in the owners maual, this should be a (fairly) straightforward job (I hope!).

Whew- to the point finally: Never having done this before, any "pearls" from those of you who have actually performed this switcharoo that you might offer before I begin surgery?

TIA-

Mike

0.8 - 1.3 bar is an ENORMOUS deadband and if that is what you had when the thing was brand new, no wonder it crapped out on you so quickly. I would consider a pstat deadband of greater than 0.2 bar to be wholly unacceptable.

In my opinion, the Cimbali branded micro pstat is a POS. The one that came with my machine needed to be replaced during the warranty period and the replacement had poor fabrication of the metal parts in which the microswitch sits. Even so, I think the deadband I got with the replacement pstat was on the order of 0.18 bar.

Your best solution would be to replace the pstat for now, and when your warranty is over, either PID the boiler and use the Cimbali pstat as a safety (set it very high but have the switching actually done by the PID), as I have done, or buy one of the new low deadband microswitched pstats to replace the Cimbali one. The new low-deadband pstats can be set to a deadband minimum of 0.08 bar. They are the same form factor as a CEME or a Mater microswitched pstat, and most probably you should wire them in with a relay owing to the power draw from the Juniors heating element.

Good luck,

ken

Hi Folks,

seems that there are people abroad with similar problems. I came along your forum by a Google search because back home in Germany apparently nobody was competent to give an answer to my problem. Maybe one of you experienced Junior Users could help?

I only recently ordered a brand new La Cimbali Junior 21 S (with water tank, no tap connector, manufactured in May 2005).

Now that I had set up the machine I found that the pressure gauge suggests an apparently strange pressure behaviour:
First, when being switched on the machine heats up and pressure rises to a max. of approx. 1,1bar. Than the pressure slowly declines to as low as 0,65 bar. Then it starts heating up again, reaching about 1,1bar again. Afterwards the whole cycle starts all over again.
Is such a deadband considered to be acceptable? My local dealer here in Germany tried to convince me that this was totally normal. My request directly at LaCimbali Italy remained unanswered (maybe they don't speak English, unfortunately I don't speak Italian either).

So maybe one of you could tell me what to do now. That would be great.

Thanks a lot and Greetings from "Old Europe"
(Please excuse my English, It's been a while that I practiced it)

Narwal

Narwal wrote:Hi Folks,

seems that there are people abroad with similar problems. I came along your forum by a Google search because back home in Germany apparently nobody was competent to give an answer to my problem. Maybe one of you experienced Junior Users could help?

I only recently ordered a brand new La Cimbali Junior 21 S (with water tank, no tap connector, manufactured in May 2005).

Now that I had set up the machine I found that the pressure gauge suggests an apparently strange pressure behaviour:
First, when being switched on the machine heats up and pressure rises to a max. of approx. 1,1bar. Than the pressure slowly declines to as low as 0,65 bar. Then it starts heating up again, reaching about 1,1bar again. Afterwards the whole cycle starts all over again.
Is such a deadband considered to be acceptable? My local dealer here in Germany tried to convince me that this was totally normal. My request directly at LaCimbali Italy remained unanswered (maybe they don't speak English, unfortunately I don't speak Italian either).

So maybe one of you could tell me what to do now. That would be great.

Thanks a lot and Greetings from "Old Europe"
(Please excuse my English, It's been a while that I practiced it)

Narwal

If your dealer really believes that a normal pressurestat deadband is 1.1-0.65=0.45 bar, then I think you should find a new dealer. This is an ENORMOUS (HUGE) temperature variation in the boiler of a heat exchanger machine and is wholly UNACCEPTABLE. This will DEFINITELY degrade the quality of the espresso you produce, and no one should spend as much money as you spent on your new machine just to get bad espresso.

I own two Cimbali Juniors; a 9 year old pourover (tank) vibratory pump version and a 2.5 year old rotary pump version that is plumbed in to the household water supply. The older machine has a Sirai pressurestat in it, and when this type of pressurestat is new or has a new membrane in it, you can expect a deadband of 0.15 bar, 1/3 of the deadband you are experiencing. It is silly to believe that a newer microswitched pstat should have a greater deadband than an old style Sirai; in fact, there are now "low deadband" microswitched pstats made by CEME that have adjustable deadbands down to 0.08bar.

The Cimbali OEM microswitched pstat in your machine is the same one as in my rotary machine. In my opinion, these are not very well designed nor executed. The problem is in the machining and assembly of the mechanical "lever-like" portion, not the microswitch itself. I would not be surprised that if you played around with the mechanical parts, seeing if they rub or catch anywhere, that maybe you can fix this problem without replacing the pstat. Another possible problem is the location of the pstat; at least on my rotary machine, it is at the very back which means you need to take off the side panels and the back panel just to access it. The lever like parts if oriented incorrectly can rub on the case itself and this can cause the problems you are observing. Mine had to be replaced and when I put in the new one I intentionally turned it around backwards so that the mechanical parts can't rub on the case back.

If you can't fix this yourself by playing with the lever like parts, tell your dealer in no uncertain terms that he must replace this part; it is defective. When the warranty has run out, you can replace the Cimbali pstat with the CEME low deadband pstat, or you can PID your machine, which is what I did to my rotary machine. I am in the process of replacing the Sirai in my old vibe machine with a low deadband CEME wired through a relay. You won't need to put a relay in the newer machine since I believe it already has one in the undertray electronics area.

Good luck.

ken