Gaggia Users Group

Hardware Discussions => Gaggias with Aluminum/Brass Boilers => Topic started by: DG Classic on December 09, 2017, 09:50:37 AM

Title: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 09, 2017, 09:50:37 AM
Hi everyone!

I have some doubts whether everything is in order with my Classic. I am pretty much new in the world of making espresso. I don't have any knowledge in engineering, electricity...way more in Art, so I am very keen in making art of an espresso :)
I have read pretty much everything and have seen videos of making and lectures of espresso world, there is a lot more but can say I am familiar with terms on what's right and what's wrong (as an amateur :).
But also as rookie I can't be sure and I can't say if something is not working the way how it should work.
What I have noticed is a different sound, that is one thing, another one is weird pouring.
Why I say weird is because I haven't found anything similar anyone recognizes when brewing espresso.

First pour is after 8, 9, 10...12 seconds, and then everything goes "normal", let's say that I aim for 1:2 ratio, some 36 gr of yield (18 gr of coffee), more or less.
So at first it looks like choking but then when it starts it ends pretty much fast. It looks like it just doesn't have enough power. Coffee is sour like it's under-extracted.

My procedure ( I have tried a few) is to flush water few minutes before brewing, and recently I've tried not to flush and what I've noticed is that I might assumed right. Brewing was better, not 100% better, but better with more regular sound, and when I rinsed PF after brewing it looked like it didn't have enough power (again) with familiar deeper sound. 
So I would appreciate some help, I know a few of you :) could solve my problem.

I would skip questioning techniques and coffee and etc...I would stick to Classic issue (this time :)
Is it a solenoid, is it a pump...or...?
Gaggia is 2002 made in Italy, no PID (yet) no dimmers, just regular Classic (ok I have changed aluminum dispersion plate with the brass, IMS shower screen) my wife and I have bought it year ago...when I became possessed  :)

Please some help!...We've been drinking rubbish coffee lately:)
 
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: D4F on December 09, 2017, 12:21:47 PM
This is a great place to start.  Though about the Silvia, most is espresso basics.

http://www.espressomyespresso.com/

Start at How to

12 - EASY GUIDE TO BETTER ESPRESSO AT HOME

Don't flush or run any water just before brewing.  Machine warm up is at least 15 minutes and 5 or minutes between brews.

Will your grinder choke the Classic, stop flow at the group?  With the double non-pressurized basket?  You should be able to set the grinder to stop flow, and then back off enough to get the flow that you need, about 25 - 30 grams, weight not volume, in 25 - 30 seconds.

Are you using coffee roasted with in 2 weeks?  Can't skip coffee in the discussion.

It will be easier to help after you supply more information :)



Title: Re: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 09, 2017, 03:10:34 PM
Thanks D4F,

Year ago I have started with readings and watching videos, I read a lot advises of professionals and baristas, I did see that article 12 - EASY GUIDE TO BETTER ESPRESSO AT HOME way ago, as I already said I've red a lot but didn't get into engineering of the machine ( but thanks for the link, it looks kind of interesting) , I know how to press brew button, but rather not draw diagram of it ( I'd rather paint a painting of Classic and brew coffee while doing it) :)

OK, let's start with this :

I make coffee (turn Gaggia on) two times a day, once in the morning and once in the afternoon.
I roast coffee myself, I have experimented with roasting (from light to dark roast) and time when to start using it (from 3-7 days, coffee is kept in a valve bag )
IMS shower screen
IMS double basket (16/21 gr) (non-pressurized) :)
Grinder Bezzera BB005 (as it shows in my profile), can grind fine to choke 5 Classics :)
Tamper 58.5 mm (Very careful concerning tamping, no visible channeling)
dosing lately from 17.6-18 gr of coffee (yield 36 gr)
Can't tell the grinder settings because Bezzera has infinite grind adjustment.

I warm Classic for 20 mins and then I switch the brew button to let some water through the group head, just enough for warming cups and get rid of stale water (about 80 ml of water), then wait around 5-7 minutes (in the meantime I am preparing everything, that's another 5 or so minutes) until I switch the brew again, in all it's 25-30 min of warming (that's the point where I noticed that the "pump" doesn't have enough power).

In my pursuit with this question I am not concerned about the taste of the coffee ( I am but...), but as I wrote I am more concerned with the sound and weird flow. It's choked at first, starts not before 8 sec, which might sound OK (5-7 sec is kind of an optimum), sometimes (depending on a day I started using roasted coffee or how it is roasted) but 8 is minimum, let's say if flow starts at 8 sec I can't have in any case 32 sec of brew time. If I target 32 sec brew time (with a bit finer grind) it won't start before 11-12 sec and so on...
I only change one variable at the time.

Until recently I didn't have this problem. I understand that the problem might be what you were referring to, but the whole thing is really weird.

OK, let me ask you a question:
Perhaps I could explain easier my doubts on your example?
Including all parameters: grind settings, dosing, tamping, what is your brewing time?
When do you hear your pump starts pumping and when do you have first start of pour?

Thanks.
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: D4F on December 09, 2017, 03:25:33 PM
Thanks for the clarification of where you are in the espresso journey.

For me, first drip about 5 seconds from "on."  Then 25+ additional seconds of brewing.

What is the volume of water combined from the group and open steam wand in 30 seconds (steam switch off)?

Remove the tank and replace it with "two tanks," a full glass of water and an empty glass for OPV return flow.  Use a blind PF or equivalent to block the group and measure flow back through the OPV into the empty glass for 30 second and note that flow.  You will then have pump flow with minimal or no resistance and pump flow at your OPV setting.  Have you ever changed the OPV pressure?  Another helpful value would be pressure at the group with a gauge, but a good start without.
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 09, 2017, 04:30:12 PM
I forgot to mention, I have a gauge and Gaggia is set on 9.5 bar (10.5 bar on gauge).

OK, that's what I meant, can't have additional 25 sec (or more) whatever I do, I can have only less, from 10 sec to 15 sec, even less sometimes, that depends on coffee roasting and the day, I change batch every 4 days. It starts like it's over-extracted almost looks like it won't start at all, but at the end with additional time it looks like under-extracted, additional time is way too short.

This looks more like a story of someone who has a bad grinder that doesn't have sufficient fine tuning, step 3 is a bit too fine and step 4 is a bit too coarse.

That's that additional time I can't have now, additional time is somehow fixed whatever I do.
If I grind finer, it will start to flow after 8 or more sec and it will end in 20 sec, if I grind even finer it will end in 25 sec, but the flow will start only after 10 or 11 sec, if I grind it coarser it will start to flow after  6 or 7 sec, but it will end then in 20 or less sec.
And this didn't happen before. The last thing that I wanted to think about was that it's Gaggia.

Title: Re: Classic, solenoid or pump issue - help needed!
Post by: D4F on December 09, 2017, 05:01:55 PM
Change batches every 4 days?  New fresh roast every 4 days or aged a little?  So you can grind too fine and too coarse and no steps between? 

In spite of beans and grinder, it worked before and you aren't mentioning any other changes.  Please check the machine/pump with the flow tests suggested.
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 09, 2017, 05:34:26 PM
Nope, as I wrote above, I start using roasted beans after they've aged 3-7 days and then use them all up in next 4 days, and I wrote a story of a bad grinder, not mine grinder :) mine has infinite grind adjustment so I can do what ever I want.
I've read about flow test you've suggested. I have a gauge but I didn't do the test still because I thought that it only tells how OPV is adjusted, not if it's working in order and if it's ready to replace it.
Could you explain please what I will find out after I do that test?

It's late here in Europe now, going to bed soon, I'll catch up tomorrow.
Have a nice day or night D4F
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: D4F on December 09, 2017, 06:11:29 PM
A healthy pump will pump about 10 - 11 ml/ml second again no resistance, so about that with the steam valve and group open - pump on.  OPV is not in play for that part.

If you have a healthy pump, then it will flow about 260 ml/minute at 9 bar.  Since you have a gauge, you can use the gauge as a blind PF, and have the pressure during the OPV flow, and use the chart to see if flow and pressure match.  In addition, since you set the pressure, it will be interesting to see if the pressure is still the same.  If off by much, you might suspect the pump.  OPV stuck open will give high OPV return and lower than expected pressure.

http://coffeetime.wikidot.com/opv-over-pressure-valve
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: JojoS on December 09, 2017, 10:55:06 PM
Apologies for jumping in but I have to ask. Have you been dealing with this issue from the start of your year long espresso journey since you got your previously owned Gaggia Classic? What kind of preventive maintenance routine have you implemented the past year?
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 10, 2017, 03:44:31 PM
Thank you  for suggestion D4F, I will try do the test during the week, I read before and it's said I can cut the process in half and measure 130 ml in 30 sec, do you think that's fine?

I will still have on my mind that it's possibly a coffee issue and not the pump.
I have some doubts in green beans that I am buying at the local shop, it's sad but true that's the only place I can buy it. I have ordered some Sumatra Mandheling from England seven days ago and hope it will arrive tomorrow or in next few days, and then I could see the difference.

Not at all Jojo, you are most welcome, any tip or suggestion is appreciated.

I guess maintaining the machine is just regular, descaling once a month or 45 days most, back-flushing with Dusty (detergent) once a week (in the same way like in the "Whole Latte Love" video), one short period I was doing back-flush only with water after every espresso because I read some recommendations, but I stopped doing that because I didn't see reason for it, only stressing the machine unnecessary.
I didn't notice or I couldn't say now if there were some issues a year ago, mostly because I had a problem like many others at the beginning, and that is grinding. 
If I try to go back and try to remember when this begun, hm, maybe it was after I bought a new (third in a year) grinder. Well after fighting almost a year with coffee and trying to grind, my wife and I finally bought a grinder which I consider decent and with a design that I love :)
OK, that's less important... Functionality matters, but I did one stupid thing (otherwise I am really careful with any device that I am using).

When the grinder finally arrived, I saw some videos or better to say one where I could find some guidelines of how to set proper grind. And that man said 25 turns from factory settings for espresso. I tried that and that wasn't even close, and you can guess what happened next, I couldn't target the right grind in the next 7-8 tries, the stupid thing was that I was so impatient and did almost one shot after another.

And maybe that way I weakened the machine, pump...do you think that's possible?

My routine is also, as I mentioned, to flush some water through the group without PF to warm cups and mostly to get rid of the stale water from the boiler and that's 5-7 min before brewing, after I dump the puck I again flush PF with basket, sometimes I attach PF in the group and flush shortly and sometimes just flush PF without locking.
I've noticed when I flush water (to clean PF) after brewing that pump pumps differently, it sounds weaker.
Maybe that's normal but I can't tell.
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: D4F on December 10, 2017, 04:54:02 PM
Yep, 30 seconds run is fine, mentioned 30 seconds in the early post.  Captured volume is different than a minute run, but calculated rate is the same.  You can do 15 or 20 seconds, but the short interval introduces more possible error.

As far as pump sounds - The pump amp or watt draw is small compared to the elements.  The pump sound may change as the heater/elements click on and off.  So, watch the heat light and see if the sound is changing with the light.

 
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 10, 2017, 05:38:27 PM
OK, that's helpful, I will do that next time, thank you.

Do you recommend flushing (cleaning PF) right after brewing or should I wait a few minutes and then clean PF, or it doesn't matter?
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: D4F on December 10, 2017, 06:23:30 PM
I don't think it matters when you clean, but that after cleaning/running the pump you wait 5+ minutes for equilibration.  I knock out and rinse the PF, and rinse grounds out of the group/screen right after a brew so that it is ready for next use soon.
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: JojoS on December 10, 2017, 09:46:44 PM
Did this flow issue start when you began using home roasted coffee?
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 11, 2017, 09:48:14 AM
It didn't quite but it did during, I did have normal flow 5-6 sec  (first drip) after turning the brew switch on, but lately can't have under 8-9 sec. I am sure that coffee (green beans) is the issue but I will have to wait, I guess, until I try with new beans when they arrive.

I think about that sound, of the weak pump. When I look at some videos where back-flushing is shown, where the brew button is being turned on-off 5-6 times in a row, can't hear that the pump looses power, like mine?

I never read any comment where people have combined problems in one shot, they have either choke, or over-extraction or they have under-extraction, it's slow or fast, but never heard any comment slow and fast in one with no visible channeling.

I did think of that and it came to my mind how that's possible even with fresh roasted coffee but low quality beans.
But can't be sure with that sound.

When I do that valve test I will know more.

I have one thing to ask about that, when should I do that, right after I turn on the machine when it's still cold, or after 5 min or more when it's heated?
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: D4F on December 11, 2017, 01:02:38 PM
Let the machine warm, but not critical as to 15 minutes.  The test is at high flow and the will cool the pump and machine a bit - cool water at faster than brew flow.  Also, since you are catching flow from the steam wand and the boiler in the same run, note the volume from each.

This test should be next.  It takes less time to run the test than to think up thread posts.  At this point, we need to find out if pump, flow, OPV and solenoid are the problem or can be eliminated.

You initial title and posts noted that you were quite sure that it was pump or solenoid.  Before chasing every thought, lets solve this one.

And yes, pump noise varies with the elements running and or with pressure building such as with back flushing.
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 12, 2017, 03:56:02 PM
Hi,

I did the test today and even before that I figure out what can be the cause, after you gave me a few tips, I've connected that the temperature has something to do with it. In short, 20-25 min is not enough to warm the machine, like I did most of the time and it worked fine, but I didn't realize that colder room (kitchen) temperature would so much prolong the warming of the machine, and honestly I never read anywhere that the warming of the machine is important for keeping the pressure for brewing. I am maybe wrong, but it seems like it was said, that warming is important for higher stability of hot water during the shot which is necessary for better espresso...

So I never read some advice like: keep in mind that if the outer space of the room is colder you will have to extend time of warming of the machine, because the PRESSURE needs hot environment to work properly... and not only coffee.

To non-engineer like me it's easy to skip such details which are implied.
Maybe I'm wrong and maybe I've just missed that detail. It's all the same to me and for those like me who might not connect those things.

That's also the reason why I am writing this, if someone somewhere would search something regarding similar confusion, maybe this explanation to myself will help them, too.

Finally at the end, after I've heated the machine for 40 min, everything was different, like it was before. I measured 132 ml in 30 sec, I did the test couple of times and it showed the same result.

Thanks a lot D4F and JojoS,

This conversation and tips helped me and led to a result, now I only have to wait for my Sumatra Mandheling to arrive from England :)

Title: Re: Classic, solenoid or pump issue - help needed!
Post by: D4F on December 12, 2017, 07:38:44 PM
I don't see where you measured the total flow out of steam wand and group, with steam switch off and no PF in.  That should be 600+ ml and a bit over half from the steam wand.  If all is well, then you may not need to bother, though that is a quick test.

I don't think that the warm up stabilization time is significantly affected by room temperature in a heated insulated house.  Warm up time for me is still about 15 minutes summer or winter.  In-house temperature is not that different, and my boiler temperature at turn on is similar. I can see boiler temperature on the PID controller as soon as I turn on the machine.  I don't see how boiler brew pressure is affected by room temperature, unless a defective pump that is affected by temperature in the machine case.  The ones that I read about have pump failing when hot, so less pressure.
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 13, 2017, 04:39:24 PM
I am a bit confused about the test you are referring, in the previous post you've mentioned the test with two cups instead Gaggia tank - one cup filled with water and the other one empty, switching the brew button and timing how many ml should come in 30 sec, you wrote : If you have a healthy pump, then it will flow about 260 ml/minute at 9 bar, right? That's the test I was writing about, and that test was OK.

So, you mentioned letting water through the group and steam as well, but I didn't know if you suggested to do both or one of them.

About warming of the machine, if you warm the machine in a room where the temperature is 20°C and if you warm the machine in room a where it's 25°C, you say that doesn't change the time of warming up of the machine?

OK, after 15 min of warming up the machine I run the other test, that 600 ml test failed because I measured about 267 ml (not each, it was combined) - it doesn't matter that first test was all right?



 
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: D4F on December 13, 2017, 07:09:59 PM

What is the volume of water combined from the group and open steam wand in 30 seconds (steam switch off)?

Remove the tank and replace it with "two tanks," a full glass of water and an empty glass for OPV return flow.  Use a blind PF or equivalent to block the group and measure flow back through the OPV into the empty glass for 30 second and note that flow.  You will then have pump flow with minimal or no resistance and pump flow at your OPV setting.  Have you ever changed the OPV pressure?  Another helpful value would be pressure at the group with a gauge, but a good start without.

Sorry that I wasn't clear.  Test 1 is with the tank in place.  Open the steam valve and then put a container under the steam wand and another under the group and run the brew switch (leave steam switch off).  This test measures flow against almost no resistance and is one test of the pump. Note the flow from each, and combined flow.

The second test, already done, is pump against resistance and was ok.

Likely test 1 will be ok, but easy to measure.  If total flow is down, then it may suggest some problem in the outflow tract, 3 way through group.  Steam valve is not usually obstructed unless a major scale problem. 
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 14, 2017, 04:32:07 PM
Hi,

I did the test as you've suggested, warm the machine 20 min and run water through the group and steam wand, it was identical 275 ml, together 550 ml, which is less than it should be I guess, not much less but less anyway. Does it tell you anything?

I also did back-flush but later, so maybe I should try the test tomorrow, again. I did notice something, water doesn't flow evenly from those small holes (dispersion plate, without shower screen), instead of that it rather goes through the middle, mostly, and occasionally appears from two smalls holes, not all four. The most amount of water goes through the middle (screw hole)? I don't know if the water should go there at all? This wasn't the case before, at least not a month ago when I removed the dispersion plate to clean it, then it flew evenly through four small holes.

I did remove it ( dispersion plate) today again to see if it's dirty, but it was completely clean. It was after I've done all, so I will see if there is any change in water distribution through shower screen.

What is the diameter of original screw for shower screen? I believe I have a ø 5 mm.


Thank you.
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: JojoS on December 14, 2017, 08:14:03 PM
Your pump is running fine. The water from the center of the dispersion disc is covered by the screw of the shower screen so don't fixate on that. If you are unhappy with the way the water is distributed out of the shower screen, you can loosen the screw a bit. Focus on improving your coffee prep techniques and just keep your machine clean like you currently do. Over and out!
Title: Re: Classic, solenoid or pump issue - help needed!
Post by: DG Classic on December 15, 2017, 11:32:58 AM
OK, then even better  :)

I'll try to write  in short where I might be wrong.
Dosing... I follow recommendations of manufacturer and always tried to stick to the higher dose of the basket can take, because I like fuller body and strength of coffee ( I knew dosing won't help much for that but I hoped it would a bit). Considering how it's roasted and the nickle test I thought everything was fine. But obviously it wasn't. I'll try to follow my instinct and eyes as well in the future, and not blindly follow only what is recommended.

I tried with smaller doses in the last two days and it has already improved.
But there is always a lot to learn, the whole process is most fun.

Thank you a lot for assistance, until the next time :)

Have a good brewing!