How to diagnose cause of dripping group?

[MDL]

Yesterday my VII (purchased from Chris in April '07) started dripping from the group and also into the drip tray. If I turn off the input water it stops. I have not yet had the chance to pull off the front panel to see which tube is dripping into the tray. I backflush with Cafiza every 2 - 3 weeks (previous Cafiza backflush on November 15); I did a Cafiza backflush yesterday after I noted the dripping but it did not cure the problem.

Any suggestions on a path to diagnose the source of this problem would be appreciated. This morning the drip tray was about 75% full after letting the machine warm up for 45 minutes.

Thanks in advance; I know that I need to determine which tube (OPV or 3 way) is dripping as one starting point.

Mark

[JohnB]

So this is dripping down from your screens? Still drips when the machine is off? Anything dripping from the expansion valve or 3 way into the tray?

[MDL]

Yes John, this is dripping from the screens even when the machine is off. To stop it I have to turn off the input water to the machine. There is also water dripping from the 3-way valve (the copper tube next to the OP valve). It is my impression that the drip from the 3-way starts before the drip from the dispersion screens (the group).

Mark

[slo]

Just looked at the hydraulic schematic and my guess is that the 3 way valve is no closing/switching properly. In an attemp to save the situation I would recommend that you backflush multiple times, to get rid of any potential contamination that may be preventing the valve to operate properly. If it is contamination than it may clear up and the valve would than close properly.

I would strongly recommend tahht you perform detergent backflush more often than every 2-3 weeks. I do it every day but I am crazy I guess.

Just a recommendation. Let me know if it helped.

[JohnB]

I'd remove & clean out the brew water control valve which is attached just above the grouphead. Could be some scale built up in there. Might also be a good time to open up the brew boiler & see whats in there. Something isn't allowing the valve to close fully. If you open the brew boiler first & find a scale build up you might be able to solve the problem just by doing a descale as the solution might dissolve whatever is in the valve before all your solution leaks out. How handy are you?

[MDL]

As John suggests, I think that the issue is clearly the brew solenoid valve at the top of the group. I did another set of Cafiza backflushes tonight and the dripping seems to have stopped. It actually was getting worse and then I did a flush with the blind basket empty, got a huge swoosh and it stopped dripping.

Back to John's suggestion of cleaning the valve, I am reasonably handy and willing to dive in with some suggestions on the route of attack. It looks pretty hard to get at the valve. Clearly the right side panel has to come off? This would be a good excuse to open the brew boiler (I have never opened it or descaled since I have always used the softener/filter system from Chris).

Any suggestions on how to proceed to get at the valve and boiler would be appreciated greatly.

Mark

[slo]

Not to be picky but the 3 way valve IS the group head valve.

From the CoffeeGeek espresso glossary (http://www.coffeegeek.com/opinions/mark ... 0-2004#101):

"Pressure Relief System: (also 3 way solenoid) on most commercial machines, prosumer machines, and many higher end consumer espresso machines, a 3 way valving system exists to immediately remove pressure from the portafilter once your espresso shot is completed. A check valve is electrically controlled: it is closed when the machine is not under operation; it opens a passage between the boiler and the grouphead and portafilter when you are brewing; and it opens a passage from the grouphead to your drip tray (or other "waste" area) once you end the brew. This system allows for quick successive brews, without any worry of a "portafilter sneeze" where the excessive pressure that remains inside a portafilter can spray hot, wet grounds all over should you remove the portafilter too soon after brewing a shot of espresso."

The fact that you had leakage on both outputs of the 3 way valve was the main clue to me.

Anyway, the problem is solve! I am happy for you.

Why would you want to take the valve apart? I do not think that scaling will ever be an issue on this valve, as it is always more or less coated with coffee oil resudue. It is when these residue collects excessivly that the valve may have a problem. hus the detergent backflush.

Now, although completly unrelated to your problem, if you want to do a check of your boiler scaling condition, that might be a good idea. It all depnds on the usage and the hardness of the water in your area. John, and others, have discovered a lot of scale deposit on there units when they checked. Others have reported almost none. Up to you.

[JohnB]

My thought was that a piece of scale from the brew boiler could have come loose & become stuck in the valve face area. I do not believe that coffee oil would have caused this problem unless the machine had gone many months without cleaning. La Spaziale uses the two screen design to trap the coffee grinds that would otherwise end up in the 3 way/grouphead valve. These screens should be swapped out every 3-4 days to clean out the accumulation. Detergent cleaning the Vivaldi on a daily basis is a complete waste of time & materials unless you are running it in a cafe. I've done a number of different length cleaning "trials" with my machine over the past 23 months & found that it takes over two weeks before you will see any brown smooge come out with the white detergent suds with the coffees I use. If it goes in white & comes out white it didn't need to be cleaned.

[JohnB]

Any suggestions on how to proceed to get at the valve and boiler would be appreciated greatly.
Mark

I'd leave the valve alone now that it is working properly & take a look inside the brew boiler. If there is no scale growing in the seam then at least you will know. My guess is that you will find enough debris floating around in there to make you wish you had cleaned it out sooner. Unlike the steam boiler where the scale adheres primarily to the heating element the nasty green scale in the brew boiler eats right into the plating & pits the boiler itself.

[slo]

My thought was that a piece of scale from the brew boiler could have come loose & become stuck in the valve face area. I do not believe that coffee oil would have caused this problem unless the machine had gone many months without cleaning. La Spaziale uses the two screen design to trap the coffee grinds that would otherwise end up in the 3 way/grouphead valve. These screens should be swapped out every 3-4 days to clean out the accumulation. Detergent cleaning the Vivaldi on a daily basis is a complete waste of time & materials unless you are running it in a cafe. I've done a number of different length cleaning "trials" with my machine over the past 23 months & found that it takes over two weeks before you will see any brown smooge come out with the white detergent suds with the coffees I use. If it goes in white & comes out white it didn't need to be cleaned.

I really doubt that it was a piece of scale, but it is possible...
Based on my exposure, the coffee gunk accumulating in the 3 way valve is the number one reason for it to fail stuck. It will not take monthes to accumulate enough gunk for a failure. If Mark was cleaning every 2-3 weeks than, to me it demonstrate that it can occur in this time frame.
I doubt that most people swap the screens every 4 days. But it is certainly good practice. Nonetheles these screens will only prevent the coffee grind to backup not the oil and the smallest particules that may collect on the valve.
Detergent backflush every day is indeed not required to prevent accumulation in the backflush path. I would say once a week should be enough in most home environment. I perform daily detergent backflush to remove any coffee residue from the group head as well as the backflush path. Coffee residue will go rancid on a hot surface quickly and may transfer a bad taste to the shots that you pull after. This may be overkill and I am still experimenting on this aspect. I will never go two weeks without detergent backflush and I hope to never see any brown "smooge". When it is visibly coming out then there was a significant amount collected and you are pushing your luck. This is not even considering what your are missing by drinking shots that are tainted by rancid oil!!!

I'd leave the valve alone now that it is working properly & take a look inside the brew boiler. If there is no scale growing in the seam then at least you will know. My guess is that you will find enough debris floating around in there to make you wish you had cleaned it out sooner. Unlike the steam boiler where the scale adheres primarily to the heating element the nasty green scale in the brew boiler eats right into the plating & pits the boiler itself.

The green color is the copper oxide that commes from the corrosion of the boiler brass material. If it looks like scale it could be because the copper oxide is depositing on scale.It's green coloured scale not green scale. The scale is not corroding the brass it is depositing on it. There are many reason for which the plating will ship off the brass. I coudn't say why yours did. But exposed brass will corrode superficially creating a green oxide layer. This is neither detrimental to the taste nor the boiler integrity (at least for a century or two). The oxide layer is actually a good protection against further corrosion, removing it will result in faster degradation.

My two canadian cents worth...

[JohnB]

The green color is the copper oxide that commes from the corrosion of the boiler brass material. If it looks like scale it could be because the copper oxide is depositing on scale.It's green coloured scale not green scale. The scale is not corroding the brass it is depositing on it. There are many reason for which the plating will ship off the brass. I coudn't say why yours did. But exposed brass will corrode superficially creating a green oxide layer. This is neither detrimental to the taste nor the boiler integrity (at least for a century or two). The oxide layer is actually a good protection against further corrosion, removing it will result in faster degradation.

My two canadian cents worth...

I'm well aware what the "green colored scale" is & I'm also well aware that it is pitting the inside of the boiler. When the scale is removed there is a pit left in the boiler where the chrome plating used to be. I don't think this is coincidence but you might. Are you aware that these are chrome plated brass boilers? The nasty scale that accumulates in the brew boiler will strip that plating. Check out the photos in this link: viewtopic.php?f=57&t=1208

[slo]

I'm well aware what the "green colored scale" is & I'm also well aware that it is pitting the inside of the boiler. When the scale is removed there is a pit left in the boiler where the chrome plating used to be. I don't think this is coincidence but you might. Are you aware that these are chrome plated brass boilers? The nasty scale that accumulates in the brew boiler will strip that plating. Check out the photos in this link: viewtopic.php?f=57&t=1208

The scale deposit is an accumulation of precipitated mineral that was suspended/dissolved in the water. When the water is transformed in steam it does not carry the suspended and dissolved minerals along. As a result these minerals tend to accumulate in the boiler and when the concentration in the water reaches a certain point the minerals precipitate and create scale deposit.

Scale does not corrode neither the plating nor the brass of the boiler. Scale will deposit more on rough surfaces (corroded or exposed brass) than smooth plating.

Any crack/scratch/defect in the plating material will allow the corrosive environment (hot water and dissolved oxygen) to contact the brass. Once the corrosion (copper oxidation) is initiated it will peel off the plating because the oxide has very adherence to the base material and the oxyde creates an expension in the volume. This is the same thing as rust (iron oxidation). You will see these thing happen most often on interfaces, edges and corners because they are most likely to have these cracks/scratches/defects.

[JohnB]

[
The scale deposit is an accumulation of precipitated mineral that was suspended/dissolved in the water. When the water is transformed in steam it does not carry the suspended and dissolved minerals along. As a result these minerals tend to accumulate in the boiler and when the concentration in the water reaches a certain point the minerals precipitate and create scale deposit.

Not much steam in the brew boiler & unlike the steam boiler these deposits are accumulating on the boiler wall instead of the element. The B/B heating element had only a light white coating of scale whereas the boiler wall had the ugly lumps of copper oxide colored deposits that seem to corroding the plating. Use your machine for a year or more, open up the brew boiler & tell us what you find.

[JohnB]

[
The scale deposit is an accumulation of precipitated mineral that was suspended/dissolved in the water. When the water is transformed in steam it does not carry the suspended and dissolved minerals along. As a result these minerals tend to accumulate in the boiler and when the concentration in the water reaches a certain point the minerals precipitate and create scale deposit.

Not much steam in the brew boiler & unlike the steam boiler these deposits are accumulating on the boiler wall instead of the element. The B/B heating element had only a light white coating of scale whereas the boiler wall had the ugly lumps of copper oxide colored deposits that seem to corroding the plating. Use your machine for a year or more, open up the brew boiler & tell us what you find. I've never found these types of deposits inside the steam boiler.

[Endo]

I would strongly recommend tahht you perform detergent backflush more often than every 2-3 weeks. I do it every day but I am crazy I guess.

Chemical backflush every day !!!!! WHAT? I don't even wash myself that often?

I bought a second dispersion puck to go with my spare set of screens. I swap the whole set once a week (following the recommendation of LaSpaziale). The only coffee and oil I find seems to collect on the sides of the brass dispersion puck.

I think water backflushes are a waste of time since the 3-way gets water through it every shot anyway.

I do a chemical backflush to dissolve any oils about once every 4 weeks. Even then, I see nothing brown in the drip tray so I may extend it to every 8 weeks.

She's a naturally clean machine by design! Don't go nuts (unless you like that sort of stuff).

[JohnB]

Endo returns!! Where the heck have you been?? Must have heard I sold my Vivaldi so you thought it was safe to return??

[Endo]

Endo returns!! Where the heck have you been?? Must have heard I sold my Vivaldi so you thought it was safe to return??

I'm just dropping in. Not much time these days for the espresso hobby.

What's that I hear?? You sold your Vivaldi? NO WAY!! I guess I'll have to go back and read the posts.

Ahhh...I see from your signature that you got the speedster! Wow!! The best!

I first thought you might have traded it in for a pair of used Roburs?

[JohnB]

Sent you a PM.

[slo]

I would strongly recommend tahht you perform detergent backflush more often than every 2-3 weeks. I do it every day but I am crazy I guess.

Chemical backflush every day !!!!! WHAT? I don't even wash myself that often?... I think water backflushes are a waste of time since the 3-way gets water through it every shot anyway. I do a chemical backflush to dissolve any oils about once every 4 weeks. Even then, I see nothing brown in the drip tray so I may extend it to every 8 weeks.

She's a naturally clean machine by design! Don't go nuts (unless you like that sort of stuff).

As you may have read in my quote... I am experimenting with the schedule of backflushing. I agree that Once a day is extreme and is unlikely to be very popular but I am running different setup to see the effect on taste of the first shot of the day. I use to do it every week on saturday and probably will return to that schedule in the near future. Clear water backflush after each session is a must for my taste.

I would recommend more often than every 4 weeks but it is up to you. It all depends on the number of shots one pulls.

Finally there is no such thing as a "naturally clean machine by design".