La Cimbali M32 Bistro problem .. driving me crazy!!

[repstein]

Greetings all,

I own a La Cimbali M32 Bistro (1 group). I purchased it used a few months ago. It appeared in great shape, but noticed the solenoid valve on the main group was allowing water to leak.

I contacted a somewhat local repair company (they are based in another part of the state, but have a local service tech). He replaced the Parker solenoid valve as well as a few other preventative maintenance issues.

A few days later, the valve wouldn't open. No water would come out.

He came by, replaced the valve again and everything was fine.

About 4 days later, the unit started leaking again. He came by, looked at the valve, and noticed it was starting to rust and the spring was a little damaged. For kicks, he replaced the valve again.

A day later (no joke), the valve is leaking again.

He tests my water and everything is normal. I have a GE Homespring whole house water filtration system as well as a salt-free water softener.

The water coming from the Cimbali however is nearing the upper limits of the test kit.

He suggests that there is scale buildup in the boiler and that the previous customer must not have had a filter. He states that his company can do it, but it'll cost over $800.

I have him replace the valve one more time, and sure enough, a week or so later, the same problem occurs.

Does this sound right? Has anyone ever experience anything like this? Any ideas?

Thanks in advance.

Regards,

Randy

 

[dchristi]

I have a Cimbali M2 system that I bought used. It worked for 2 years. Next thing I know it quit dispensing hot water from the water spout. I replaced a valve and noticed it didn't help much. After talking to a tech I realized I need to take the unit apart and soak the tubes in a descaler. This was a major task, but Once I got into it it wasn't all that bad. I did find it had lots of buildup throughout the water lines. Mine also had a tiny screen filter that need to be replaced. I had no choice but do it myself. There are no techs or companies within a 200 mile radius of my store.

My issue now is getting the coffee programming down correctly to have it produce a good quality coffee. Seems that no one out there really understands all of the settings: water dose, coffee dose, Backing, Infusion, Prs. discharge, drying and water after settings. Any help with that would be great. manual only tells you how to change, but in my case I think someone went in and changed it all not knowing what they were doing.

 

[CCafe]

Okay this is off the top of my head.

Type - for personalizing that key
water dose - sets the amount of water to pass through the grind, 100 pulses should be about 1 ounce after after saturation
MSX or MM1 - left grinder - sets the amount of ground espresso going into chamber - you need to weigh the coffee to get exact measurement of the number system. Start at 70.
MDX or MM2 - right grinder - same as above
Backing - After the piston tamps this pulls the group down in increments. Theory more backing more room for crema on types of espresso that are harder to produce creama on super auto's.
Infusion - the amount of time water will pass through the grounds with no pump pressure applied. 2 to 3 seconds is standard. Moving up and down will affect shot time.
pressure discharge - don't adjust
drying - if you have soupy pucks increase drying time. if you have pucks that crumble to dust decrease drying time. Standard time is .2

Weighing section requires a gram scale. after you set your varriables weigh your coffee 3 times. You should be shooting for 14 grams on a double shot. Chamber only holds 18 to 20 grams. Once you hit 14 go back to the key menu button, hit the information button to test your shots 3 times. Average the shot times. If your way to fast adjust grind, reweigh coffee, once you hit 14 grams on average return and test button again. Keep repeating until you have a 20 second shot or longer depending on your needs. For fudging factor you can increase or decrease MM1 or MM2 quantity if you feel you have the grind just right to increase or decrease weight of coffee.

 

[CCafe]

Also Cimbali dictates that 3 grains or less of water hardness is require to operate your espresso machine. If your using a water softener your system will scale up within 4 to 6 years. So you will need a general over haul/descale to keep your unit running. No matter how much people tell you RO sucks, if you dial it in to give you between 70 and 150 TDS your machine will look pretty much new inside even after 10 years.

Remember TDS is not the same as looking at your scale stick that says you have xx grains and xxx PPM. TDS measure total dissolved solids in ppm, using a Hach testing strip only measures the ppm of CaCo3. People see this and try to say my TDS of my water hardness is xxx ppm. Sadly these two numbers are not the same and its a mistake you will pay dearly for in the long run. You can have 170 ppm TDS while having 30 grain water that would be about 450 ppm. At 30 grains your espresso machine in about 6 months will have the same build up as a machine supplied with soft water has in about 3 to 4 years.

 

[dchristi]

Thank You for the Response CCAfe!

Also Cimbali dictates that 3 grains or less of water hardness is require to operate your espresso machine. If your using a water softener your system will scale up within 4 to 6 years. So you will need a general over haul/descale to keep your unit running. No matter how much people tell you RO sucks, if you dial it in to give you between 70 and 150 TDS your machine will look pretty much new inside even after 10 years.

Remember TDS is not the same as looking at your scale stick that says you have xx grains and xxx PPM. TDS measure total dissolved solids in ppm, using a Hach testing strip only measures the ppm of CaCo3. People see this and try to say my TDS of my water hardness is xxx ppm. Sadly these two numbers are not the same and its a mistake you will pay dearly for in the long run. You can have 170 ppm TDS while having 30 grain water that would be about 450 ppm. At 30 grains your espresso machine in about 6 months will have the same build up as a machine supplied with soft water has in about 3 to 4 years.

CCafe- I want to say thanks for the advise! Most of these forums don't see to get much interaction with members.

Your information was very helpful! I will get a good gram scale and weigh the coffee. I finally got a hold of a Cimbali Tech and he got me real close on the settings.

I'm still having issues with the pressure though. I have totally went through through and descaled everything as of yesterday. I'm told I should be around 9 bars when it is making an espresso. My unit is always around 5 bars. I checked everything and tried to make adjustments on pump and another flow valve on other side of machine. I see no change what so ever when making adjustments on either of the vavles. I just finish descaling the last little section I had not done originally. It was from flow valve on left side to the first solenoid. Looking at schematics I found a needle valve that was not even suppose to be in the line. I took it out and I will be testing tomorrow.

 

[dchristi]

One last thing- This machine was bought used from a friend of ours that owned a tea/coffee house. She was not very good at providing TLC to her equipment. It now works as it did when I bought it. However, I have never seen the crema when it makes the espresso shots. It does the milk frothing and foam great! But the shots have never come out looking like they should- light brown (I'm guessing this is the crema?) I'm thinking the 9 bar has something to do with it?

 

[CCafe]

Pull the right side panel off. You'll see the pump with locking nut. I think its a 22. The nut underneath the adjustment is the part that holds the whole assembly. Shut the water off. Remove that lower nut. That will take the adjustment screw and locking nut off the top. Now inside that part you'll find a little plunger. Here's the hard part! Put the plunger on the counter and gently push down. That will loosen it so you can pull it out. Clean the oring and relubricate it with some vaseline or food grade lubricant. Reinstall it.

Now you'll be able to make pressure adjustments to your M2. Loosen the locking nut and rotate both directions so you know which way is pressuring the system up and down. Now just run 2 - 3 shots out and set your pump pressure to 9 bar.

 

[dchristi]

Setting Pump Pressure

Pull the right side panel off. You'll see the pump with locking nut. I think its a 22. The nut underneath the adjustment is the part that holds the whole assembly. Shut the water off. Remove that lower nut. That will take the adjustment screw and locking nut off the top. Now inside that part you'll find a little plunger. Here's the hard part! Put the plunger on the counter and gently push down. That will loosen it so you can pull it out. Clean the oring and relubricate it with some vaseline or food grade lubricant. Reinstall it.

Now you'll be able to make pressure adjustments to your M2. Loosen the locking nut and rotate both directions so you know which way is pressuring the system up and down. Now just run 2 - 3 shots out and set your pump pressure to 9 bar.

Sorry for responding so late. I had to order some parts for the machine.
I did everything you mentioned on the valve and then made the adjustment on the pump and the flow valve. However, I saw no real change in pressure. I took a needle out that goes into the volumetric valve and I did see an increase in pressure from 4 to 6 bars. However, still not enough to help. I did notice that the braided line going from the pump to flow valve had a nasty kink in it. I was hoping replacing the hose would fix my pressure problem- Not. I could blow into the old hose and when it was bent I did see major air flow restriction.
PS- I also put a new boiler fill sensor in the unit. I thought my old one was bad. I pulled it out and the rod was straight. After receiving the new sensor I realized that the old one did not break, but was straight at the end instead of being bent.

Have you heard of the pump going bad on these units? Not sure what else to do to resolve the pressure issue?
PS- The unit works correctly for everything else.
Because the pressure is so low I'm not getting the crema in the espresso shot as you would expect in a espresso shot.

 

[CCafe]

Well if the pump is physically rotating you should have been able to adjust the pressure. Before ordering and replacing the pump test your capacitor on the motor. Make sure its roughly 5uF. If you can't test the capacitor go to your local hardware store and buy a multimeter that has a capacitance setting. Most $30 multimeters have this setting. If the capacitor is showing 3.5 - 4uF or even less then you're going to need to replace it. You can replace it with a 5, 7 or even a 10uF cap. Much higher than 10uF you'll notice your motor has a lot more torque action happening and it will eventually tear out your motor mounts plus its a tad hard on the motor too. I would go this route before replacing the pump. Meter and cap will set you back about $50. A new pump is pushing $400.

Pumps do go bad. Under normal wear and tear (filtered and softened water) they can last up to 10 years sometimes longer. Machines that were pulled from service and shelved with water in the pump will reduce its life expectancy.

 

[dchristi]

Well if the pump is physically rotating you should have been able to adjust the pressure. Before ordering and replacing the pump test your capacitor on the motor. Make sure its roughly 5uF. If you can't test the capacitor go to your local hardware store and buy a multimeter that has a capacitance setting. Most $30 multimeters have this setting. If the capacitor is showing 3.5 - 4uF or even less then you're going to need to replace it. You can replace it with a 5, 7 or even a 10uF cap. Much higher than 10uF you'll notice your motor has a lot more torque action happening and it will eventually tear out your motor mounts plus its a tad hard on the motor too. I would go this route before replacing the pump. Meter and cap will set you back about $50. A new pump is pushing $400.

Pumps do go bad. Under normal wear and tear (filtered and softened water) they can last up to 10 years sometimes longer. Machines that were pulled from service and shelved with water in the pump will reduce its life expectancy.

Thanks for the quidance!

I had a couple of multimeters. but not one that checked the capacitance. I picked up a decent one at Lowes today. The capacitor is rated at 5 uF, but is only reading 2.047 uF. Looks like that might be the culprit. I'll order a new one and let you know how it turns out. That also explains why I cannot see any change in pressure/bars when making the adjustments. It is running about 1/3 of its power.

 

[CCafe]

What the capacitor does is give the motor and extra kick of stored energy to get it over the hump of the internal resistance caused by the water pressure in the pump. Sadly at 2uF that capacitor was no longer able to do this so what was happening is your motor just stalled out. So its good you're getting this changed now as a stalled motor will eventually burn out.

 

[dchristi]

Low Pressure Problem

Thanks for the quidance!

I had a couple of multimeters. but not one that checked the capacitance. I picked up a decent one at Lowes today. The capacitor is rated at 5 uF, but is only reading 2.047 uF. Looks like that might be the culprit. I'll order a new one and let you know how it turns out. That also explains why I cannot see any change in pressure/bars when making the adjustments. It is running about 1/3 of its power.

Well, finally after two weeks I got the capacitor in. UPS lost the package! I tested the new capacitor and it was reading 5.3 uF- GREAT. However, after installing it the pressure only went up about a bar. It now reads 5 bars. I tried to adjust on the adjustment screw, but did not see any real change. Any other areas that I could look at? At one point I had one of the needle out that went into the volumetric unit. And it was giving me higher pressure rates than with the needle in the system. Do you think I should try taking that out? It is clean and I can see through it. So there is nothing clogging the needle.

At this point I'm not sure what to do next?...

 

[CCafe]

You can try adapting a pressure gauge or buying a new pressure gauge to see if that's the problem. I'm leaning more towards that you have a pump issue. Pumps go bad, this may be what is wrong with yours. A new pump is about $400 for the M2, however a new M2 is about $18,000, I'd say $400 is a small investment.

There is a small chance that all this is the motor's fault. Normally though when your motor is dying it won't turn with the pump installed and will run fine with nothing attached. I'd venture to lay my blame on your pump.

 

[dchristi]

Well if the pump is physically rotating you should have been able to adjust the pressure. Before ordering and replacing the pump test your capacitor on the motor. Make sure its roughly 5uF. If you can't test the capacitor go to your local hardware store and buy a multimeter that has a capacitance setting. Most $30 multimeters have this setting. If the capacitor is showing 3.5 - 4uF or even less then you're going to need to replace it. You can replace it with a 5, 7 or even a 10uF cap. Much higher than 10uF you'll notice your motor has a lot more torque action happening and it will eventually tear out your motor mounts plus its a tad hard on the motor too. I would go this route before replacing the pump. Meter and cap will set you back about $50. A new pump is pushing $400.

Pumps do go bad. Under normal wear and tear (filtered and softened water) they can last up to 10 years sometimes longer. Machines that were pulled from service and shelved with water in the pump will reduce its life expectancy.

For some reason my last post did not make it online to the thread....

UPS lost the capacitor I purchased for a two weeks. Now I have it and it test out at 5.3uF. However, it did not solve my pressure problems. The pressure went up about one bar (4 to 5), but noting I do on the adjustment seems to increase pressure. Any other suggestions? Does the volumetric sensor/unit ever go bad on these units?

 

[CCafe]

You can try to replace the pressure gauge but I think you're at the point that you are going to have to just call it what it is. Sounds like its time to replace the pump.