The boiler fill solenoid may be stuck open or leaking... letting water continue on into the boiler indefinitely.

Eric posted this link the other day to a good site with commercial machine info including some solenoid details (and older Cimbali Junior diagrams):

http://members.lycos.nl/behindespresso/ (sites seems happier in Internet Explorer)

You machine fills via water pressure (not pump), the inlet water enters some sort of check valve and then the boiler and/or dosing chamber depending on the the state of the boiler and dose chamber fill solenoids.

Water pressure regulation (and conditioning) is advisable, but not likely to be the sole cause of your current issue.

Thanks for the info/link. I'll have to check out some more parts and hopefully figure out what the problem is. I had water all over the place which wasn't too fun, but this is a learning process for me.

Update: I went to check out the solenoid valve that is connected to the copper pipe that runs up the bottom center of the boiler. I removed the nut and coil, then the four screws that held the base of the lucifer (?) and that's where I ran into a problem. I forgot to drain the boiler from my last test, so water started shooting out all over the place. I ran to grab a towel and didn't notice which way the piston piece faced when it's inside the lucifer piece. I'm not even sure if I'm using the correct terms but there are only two options to put this back together and I don't remember seeing which way it went. I normally take pictures of all that so I can check back but with the water flowing out I needed to take care of that quickly and the parts weren't together when I came back. What a pain, but does anyone know which way it should go together? I took pictures of the two options, and the piece sticking out of the piston end is a spring if it's hard to tell. I didn't notice anything odd when I took it apart so I can't tell if it's working properly or not. Maybe this thing is more than I can handle since all these parts are pretty new to me, but I've been trying to learn from other posts and sites and didn't notice any pictures of this valve. Thanks for any help.

The spring should be such that the valve is held closed, so the lower pic looks right. Energizing the solenoid coil counteracts the spring and opens the valve.

Here's a picture and link to an explanation of a 2-way solenoid valve.... (I had some trouble finding legible cutaways).

burkert.com wrote:Plunger-type solenoid valves, 2/2-way
Direct-acting 2/2-way plunger-type solenoid valves (e.g. Burkert Types 6011 and 6013), also referred to as through-way valves, are shut-off valves with two ports: one inlet P and one outlet A, see Figure 1: Inlet P is connected to the pressurized fluid or gas. In the de-energized state, the core spring, assisted by the fluid pressure, forces the solenoid core (plunger) with the valve seal onto the valve seat; passage to outlet A is thus shut-off. If voltage is applied, the solenoid core with the valve seal is pulled into the coil as the result of the magnetic force and the valve opens; the passage is unobstructed again.

Flow direction


Figure 1 - 2-way solenoid valve - Closed (coil de-energized, spring holding plunger/piston down), flow from left to right


Figure 2 - 2-way solenoid valve - Open (coil energized), flow from left to right

And here's a link to a 3-way valve operation explained here: http://www.burkert.com/COM/384.html (Fun stuff, eh?)

Spresso_Bean wrote:Maybe this thing is more than I can handle since all these parts are pretty new to me, but I've been trying to learn from other posts and sites and didn't notice any pictures of this valve. Thanks for any help.

Don't give up, think of it as a learning/personal growth experience. I was never very mechanically-minded until it was forced upon me in a production factory setting... it can be learned!

EDIT - Here's a helpful troubleshooting guide for solenoids: http://www.mt-online.com/articles/0204parker.cfm#table

Wow, thanks for the lengthy explanation and more details/links and that's really helpful. I see what you mean about the way it "opens" when energized - pretty interesting how they work. I haven't given up yet and if anything I'd put it aside for a while as I learned more about everything and why certain parts might not be functioning properly, testing them, etc. I really appreciate the help.

My latest work on the Junior was taking the heating element out since during testing I noticed a slight leak around the seam between the boiler and element mounting plate. I took the element out and noticed that the gasket was deteriorating and should probably be replaced. The gasket was just about fused to the boiler opening and I had to scrape most of it out with a small flathead screwdriver. Hopefully the little scratches in that area won't cause leaking issues later on but I couldn't think of another way to get the gasket out. Anyone have suggestions for cleaning that area out from the old gasket?

I haven't taken the brass group assembly and HX apart because I figure if it's not leaking then I should leave it alone. Not only that but I've seen a few reports of multiple o-rings being necessary but most of the diagrams I've seen, including the Cimbali manual for the Junior, only show one o-ring and two flat gaskets for that area. Well anyway when choosing gaskets there are paper gaskets and Teflon gaskets, the Teflon are around twice the price. Is it worth the extra cost for the Teflon or are the paper better? Before I go ahead and order some I thought I'd ask if anyone feels one is better than the other. It also looks like the same gaskets are used for both the heating element and the group/HX area. I'm hoping to get this thing up and running pretty soon but I've been taking my time and am still not sure if the boiler fill solenoid issue has been fixed. I took it apart and cleaned it but if that doesn't work then maybe it needs to be replaced. Thanks for any info-


PS added by moderator: Cross-posted to CG as Gaskets - Teflon or Paper?

Thanks to everyone here that helped with tips, ideas, links, etc. - last night I put the last parts together and started the Junior up. To my surprise it worked perfectly and I even pulled a shot with it (old beans just to test). The issue with the water overflowing was the boiler fill solenoid and at one point I took it apart and cleaned everything out, stretched the spring a bit, and it works fine now. Replaced the heating element gasket with a paper/RTV combination and it hasn't leaked. The only main part I didn't touch was the seal between the group assembly and the boiler/HX since it seemed fine and I didn't want to mess with that. Anyway, it works great and after a while of disassembly, descaling, and cleaning the interior it's a nice feeling that nothing is leaking or malfunctioning. Now to the exterior, which is brass and a bit banged up in some areas - I was thinking of refinishing it with some high heat engine paint. Would that be a disgrace to the upgraded brass panels? The paint I found is a charcoal gray and I think that would look better. Thanks again to everyone that contributed.

Ok, well I've been using my Junior for a few good months once up and running, and I notice that when I go to steam milk that the steam isn't all that powerful, and it seems less powerful than my little Gaggia Evolution. It's plenty hot (the steam) and I plugged two out of four holes in the tip because it was heating the milk too fast, but overall I can't get a really good powerful whirlpool when compared to the Gaggia which works really well for milk. Any ideas on what to check in this case? I dialed down the pressurestat a while ago but that was about the only adjustment I made. Is the Junior's steam power just not that great or is this something with just my machine? I guess it could be scale in the lines but that line begins near the top of the boiler and I had no idea how to run the acid solution through there long enough to clean it out. I was really just curious if the Junior should have really powerful steam, as I was expecting the "painting the walls and ceiling with milk" type of experience but it's fairly weak in my opinion. Using all four holes in the tip doesn't give me any more of a whirlpool, and just heats the milk quicker. Any help is appreciated. Thanks.

Spresso_Bean wrote:Ok, well I've been using my Junior for a few good months once up and running, and I notice that when I go to steam milk that the steam isn't all that powerful, and it seems less powerful than my little Gaggia Evolution. It's plenty hot (the steam) and I plugged two out of four holes in the tip because it was heating the milk too fast, but overall I can't get a really good powerful whirlpool when compared to the Gaggia which works really well for milk. Any ideas on what to check in this case? I dialed down the pressurestat a while ago but that was about the only adjustment I made. Is the Junior's steam power just not that great or is this something with just my machine? I guess it could be scale in the lines but that line begins near the top of the boiler and I had no idea how to run the acid solution through there long enough to clean it out. I was really just curious if the Junior should have really powerful steam, as I was expecting the "painting the walls and ceiling with milk" type of experience but it's fairly weak in my opinion. Using all four holes in the tip doesn't give me any more of a whirlpool, and just heats the milk quicker. Any help is appreciated. Thanks.

You should have more steam than you can use in a home setting with this machine, so something is wrong.

Possibilities include:

(1) Autofill is filling the boiler way too high, beyond half full, which will give you a small quantity of moist steam, especially if the boiler is well beyond half full.

(2) Pressurestat set too low. Assuming your front panel gauge is working properly, any setting much below 1 bar will be hard to steam with

(3) some occlusion or other problem in the steam line from the boiler.

(4) your plugging of the steam holes. This is not necessary and is probably counterproductive. The old style Cimbali steam tips are good only for spraying milk on the ceiling. Unless you have a modern one, from the last 5 years or so, you should buy one. And you won't need and should not block any of the steam tip channels.

ken


New style Cimbali steam tip

Thanks for the input, and I'll look into it more in the morning. My Junior is one of the older styles like your brass-bodied version but plumbed in. I bought a replacement steam wand from EPNW so it's probably an Ascaso part and it came with a tip that's different than what's in the picture above. It's a four hole tip and maybe it would be best to remove the toothpick plugs and keep practicing, but without the plugs it would literally heat the milk in maybe 5-10 seconds and I never had any microfoam. I mainly use it for espresso but sometimes like to make a milk drink or two. Thanks for the suggestions - I think the pressurestat was adjusted to around 1 bar on the front gauge and that was as low as it went before the adjustment screw popped out. I'm still getting used to how the Junior works so I'm learning, but it's great other than with the steaming.

Is there an ideal setting for the pressurestat when viewing the front gauge on the Junior? I thought I read that around 1 bar or less is ideal which is why I dialed it down. The boiler fill probe is down in the boiler as much as possible but I don't have the actual measurement of the probe - I just used it the way it came and adjusted it as far into the boiler as I could so I'd guess it's filling maybe 2/3 of the way up but that's as low as I could get it without trying to find a longer probe. The occlusion, well I'm not sure how to even go about checking for that other than eliminating the other possibilities. Thanks again for any help.

Spresso_Bean wrote:Is there an ideal setting for the pressurestat when viewing the front gauge on the Junior? I thought I read that around 1 bar or less is ideal which is why I dialed it down. The boiler fill probe is down in the boiler as much as possible but I don't have the actual measurement of the probe - I just used it the way it came and adjusted it as far into the boiler as I could so I'd guess it's filling maybe 2/3 of the way up but that's as low as I could get it without trying to find a longer probe. The occlusion, well I'm not sure how to even go about checking for that other than eliminating the other possibilities. Thanks again for any help.

Assuming the FPG is accurate, a well functioning Sirai pstat membrane should have a "deadband" of approximately 0.15 to 0.2 bar; this is not user settable, but if more than 0.2 bar, one should think along the lines of replacing the membrane, an easy repair task. If one is making a lot of milk drinks, the upper part of the deadband could be as high as 1.2bar, but I would not go any higher than 1.25 bar as the quality of the straight shots will deteriorate or you will need to use very large flushes.

If you are making straight shots primarily, then you could set the upper part of the deadband as low as 1.0 bar, but you might want it a little higher if you are going to do any milk frothing.

The autofill probe can become coated with scale, which will cause the boiler to fill to a level higher than the lowest point of the probe, which is where the autofill SHOULD shut off. Using the sight glass level in my old vibe Junior as a guide, when I drain the boiler at the lowest acceptable level (as marked "Min" on the front panel adjacent to the sightglass), I get between 8 and 10 oz. of water through the water wand (do this just after turning the machine off; since yours is connected to the mains, turn off the water so that there is no water leakage past the input solenoid into the boiler which may obscure your measurement). At the mid point I will get about 16, maybe 18 oz. If you are getting more than about 18oz out the water wand when you do this, then your boiler is filling too high.

Note that this is NOT the total amount of water in the boiler at these fill levels; it is simply what will come out passively through the water wand, when the boiler is heated up and pressurized.

ken

Thanks for the insight, Ken. I feel like I still have a lot to learn with how some of the components work, but I appreciate the help. I love how easily the panels can be removed to access the internal parts, and it only took me a few minutes to adjust the Sirai and get it back together. It's great, and I'm trying to work with the adjustment and so far the steaming is noticeably better so that's a good sign.

I acquired a used Cimbali Junior over the weekend. Looks like you have gone through this process already, and I am hoping you can help. I have a water line hooked up, and everything seems to be functional (steam wand, hot water, auto fill, etc.). Two things I am wondering:

1. The boiler pressure continues to climb into the red zone. How do I adjust it?

2. I am only getting a steady stream of steam from the group head. I removed the screen and shower plate (?) and will replace those. So its just steam coming from the group head itself.

I am new to this, so technical terms will only confuse. I do not have a manual, so when you are referring to particular parts, a picture or description of location with help a lot!

Thanks for you help in advance. I cant wait to pull the perfect shot from this beauty!

jthiessen8 wrote:I am new to this, so technical terms will only confuse.

Have you considered having it professionally serviced? The problems you list can have multiple causes.

Thought about it. There is a servicing partner is town. But I would like to try my hand at it first.

jthiessen8 wrote:Thought about [getting professional service]. There is a servicing partner is town. But I would like to try my hand at it first.

Remember that water + heat + rising pressure = the potential for an explosion with serious, life-threatening implications. If you don't know what you're doing, get the professionals involved.

I agree with Richard, this is a used espresso machine with known problems. There may be other problems that you have yet to discover, some of which could compromise the machine's safety. Maintenance of used equipment is notoriously bad and the problems you cite do not inspire confidence. Have it professionally serviced, you will thank us later.

OK, i hear your message on the boiler issue. Perhaps I will consult the local servicer. Is this something you, yourself, would not undertake? Is this an unusual issue? I played with the pressurestat a bit to see if I could adjust it. I may dismantle the components to see if I can clean things up a bit.

On the group head, I was able to take it all apart and clean it. Turns out the solenoid on the side was clogged. Put it all back together, and now I have hot water flowing!

Next issue, the dosing chamber in the back (the clear plastic box with metal rods). I want to take it apart and clean it as there is a heavy buildup of black gunk. How do you suggest I take it apart? Also, as the hot water is dispensing from the group, should the water level in the dosing chamber fall? It seems like nothing is happening in there when the water is flowing.

Thanks.

jthiessen8 wrote:Is this something you, yourself, would not undertake? Is this an unusual issue?

Well, we're talking about you, not me. I've done home projects with elements of framing, plumbing, and electrical work, but I know where to draw the line. For example, I called a licensed electrician to add a new circuit breaker and an experienced iron pipe installer for adding a natural gas line extension; not because I couldn't figure it out how to do it myself, but because the risk of screwing up wasn't worth saving the one-time installation cost.

You said this Cimbali Junior is used with an unknown maintenance history and "I am new to this, so technical terms will only confuse." You may fix what's obviously wrong, but there could be hidden issues that only a seasoned repair technician would know to check. My advice is unchanged: Get it professionally serviced, top to bottom. From that point forward you can do your own maintenance if you desire.