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Getting to the end of my tether, please help (slow/no pull)

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Hello there. This is my first post after much browsing and reading. Hope you don't mind getting straight down to my problem?

 

I bought a used Gaggia Classic about 18 months ago and have always had issues despite the previous owner having none whatsoever. The main issue is, often I will get nothing from the machine but a few drips of coffee. Every now and then I will get a good pull in around 35-40 seconds which tastes fine so I keep all my grind settings identical and then the next time, nothing or just a few drips. This happened again yesterday.

 

Spoke to a very helpful chap in my local shop, bought some Deerhunter beans (fresh) left my grinder on it's previous setting but this time did as he said and used 18g like they do in the shop. In 35 seconds, I had a delicious coffee. Nailed it, I thought. Next time, same settings, same tamping, nothing. Tried again, nothing. Left it until today again again, nothing but a few drips.

 

SO I have now cleaned, backflushed, descaled, tested flow rate 300ml in 30 seconds, cleaned behind the shower screen and the thingy behind that and low and behold, exactly the same. Tried different grind settings on the Smart Grinder Pro, different weights of coffee from 14-18g and very inconsistent. At anything from 16-18g, the puck seems to be hitting the screw in the centre of the screen which is why I tried a little less.

 

The last settings I tried was 14g at a 22 setting on the grinder and managed just short of a double shot in 40 seconds but it didn't taste great.

 

I would LOVE some advice from you experienced folks and look forward to reading any replies.

 

Many thanks.

 

I welcome any advice anyone can give with this because I just want to be able to pull consistent coffee.

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You need to weight your output.

Ie what is currently your "double shot " .

A tasty shot isn't 60ml or 2 FL ounces for everyone or every bean . Weighing the espresso out will help you set a recipe a a coffee to water ratio that helps

Check the barista skills thread and the sticky on weighing and brew ratios .


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right, you need to do the flooring, which will not cure but help to understand. You first of all need to learn to repeat the shot, so you are quite right, keep everything the same. Use the same bean, same grind setting, same tamp level. if those are constant, then the shot produced ought to be the same each time. Vary any one of those and the results will differ. From memory, the standard classic basket works well around 18 grams. The grinder you have is sufficient but no more. try to alter the grind settings my no more than a single digit and remember or record the differences. If needed, then get a big bag of coffee and play with the settings making small incremental changes to the grind if needed. But, remember, espresso is extracting, so start off with a 2:1. This means if you put 18 in take 36 out so you need to weigh. You then have the option of varying the ratio to adjust to your taste

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All these responses are guesswork, but here's my guess FWIW. I rebuild and upgrade Gaggia Classics (and a few Baby's) regularly. One of the most common faults on a machine more than a couple of years old is partial blockage of the restrictor jet, which is part of the flow path out of the boiler. The jet nozzle is around 0.8mm diameter and the flow passages around it are all small bore drillings. This jet has a rubber seal sitting on it until the pump has pressurised the boiler. So its a perfect location for limescale to build and get lodged. Small pieces of scale can cause the problem you are describing.

You'll need some mechanical skills and method to safely remove the stainless steel outlet casting, it needs really thorough cleaning. If that is the problem, the boiler needs opening also to descale and remove any more loose scale and particles from the brewed passages, that could cause a return of the same problem.

There are one or two other defects in the pump and the flow/return loop that can cause these symptoms, but this is a good place to get right, on a well-used machine.

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Have you discounted there being a mechanical fault? I'm not saying it is, but it could be a faulty pump, where it can push the volume with little resistance but struggles with the resistance provided by the coffee puck, or something stopping the three-way valve from closing properly.

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You need to weight your output.

Ie what is currently your "double shot " .

A tasty shot isn't 60ml or 2 FL ounces for everyone or every bean . Weighing the espresso out will help you set a recipe a a coffee to water ratio that helps

Check the barista skills thread and the sticky on weighing and brew ratios .

 

14g in that bakset with that grinder will i suspect be too small a dose too

 

Thank you for your response. I will check the thread you mention. :)

 

right, you need to do the flooring, which will not cure but help to understand. You first of all need to learn to repeat the shot, so you are quite right, keep everything the same. Use the same bean, same grind setting, same tamp level. if those are constant, then the shot produced ought to be the same each time. Vary any one of those and the results will differ. From memory, the standard classic basket works well around 18 grams. The grinder you have is sufficient but no more. try to alter the grind settings my no more than a single digit and remember or record the differences. If needed, then get a big bag of coffee and play with the settings making small incremental changes to the grind if needed. But, remember, espresso is extracting, so start off with a 2:1. This means if you put 18 in take 36 out so you need to weigh. You then have the option of varying the ratio to adjust to your taste

 

Thank you. Yes, I did the same thing between shots which is why it's so frustrating. The first one was just right, the one after was barely any output at all. We are talking a few ml at most. It's a shame to hear that about the grinder being only sufficient. I don't want coffee shop level by the way, but for the price I would have expected a little more than that I guess. Plus it was a gift last year. :(

 

When I use 18g, which is what my local coffee shop uses for that beans, I have had a really good extraction as I said but it also hits the screw in the shower head which I have read on here is too full. See why I get confused?

 

All these responses are guesswork, but here's my guess FWIW. I rebuild and upgrade Gaggia Classics (and a few Baby's) regularly. One of the most common faults on a machine more than a couple of years old is partial blockage of the restrictor jet, which is part of the flow path out of the boiler. The jet nozzle is around 0.8mm diameter and the flow passages around it are all small bore drillings. This jet has a rubber seal sitting on it until the pump has pressurised the boiler. So its a perfect location for limescale to build and get lodged. Small pieces of scale can cause the problem you are describing.

You'll need some mechanical skills and method to safely remove the stainless steel outlet casting, it needs really thorough cleaning. If that is the problem, the boiler needs opening also to descale and remove any more loose scale and particles from the brewed passages, that could cause a return of the same problem.

There are one or two other defects in the pump and the flow/return loop that can cause these symptoms, but this is a good place to get right, on a well-used machine.

 

Thank you. I am quite handy and practical with such things so taking bits apart to check shouldn't be a problem. I will look into what you describe if I can figure it out.

 

Have you discounted there being a mechanical fault? I'm not saying it is, but it could be a faulty pump, where it can push the volume with little resistance but struggles with the resistance provided by the coffee puck, or something stopping the three-way valve from closing properly.

 

Nope, I haven't discounted that at all. I figured after doing all the cleaning, descaling, back flushing and keeping my grind etc the same, this would be the next port of call. :)

 

I have read what you describe before. The output is fine with just the pump running, but add the strain of a full basket and it may slow.

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Thank you for your response. I will check the thread you mention. :)

 

 

 

Thank you. Yes, I did the same thing between shots which is why it's so frustrating. The first one was just right, the one after was barely any output at all. We are talking a few ml at most. It's a shame to hear that about the grinder being only sufficient. I don't want coffee shop level by the way, but for the price I would have expected a little more than that I guess. Plus it was a gift last year. :(

 

When I use 18g, which is what my local coffee shop uses for that beans, I have had a really good extraction as I said but it also hits the screw in the shower head which I have read on here is too full. See why I get confused?

 

 

 

Thank you. I am quite handy and practical with such things so taking bits apart to check shouldn't be a problem. I will look into what you describe if I can figure it out.

 

 

 

Nope, I haven't discounted that at all. I figured after doing all the cleaning, descaling, back flushing and keeping my grind etc the same, this would be the next port of call. :)

 

I have read what you describe before. The output is fine with just the pump running, but add the strain of a full basket and it may slow.

The standard gaggia double basket is smaller than 18g. It's alot coser to 14g. The 58mm portafilter is the same size as commercial e61 groupheads so there are lots of baskets available. I use an 18g VST myself most of the time.

Your grinder is going to have a bit of retention between grinds so it can take 1 or 2 shots after changing the grinds to settle into it's setting. Maybe that's why it was ok 1 shot then too fine the next.


Laissez les bons temps rouler

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I would also check the three way valve very carefully for loose scale (pinhead grains can be enough) as this could stop the flow. Normally when it happened to me it was a constant rather than intermittent fault but a piece of scale big enough to block the outlet but not get into it could cause an intermittent issue. Photo of mine when I took the boiler out below. I write on all the connectors with permanent marker to show what goes where. Makes it much easier connecting it all back up again :)

 

A929EB96-225F-42DA-A4BF-7FD08717D404.jpg

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To the OP, one of the key bits of information you can give to get a good diagnostic is the age of the machine....


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Thank you but I don't actually know seeing I bought it used.

 

Some good news though, I managed to wire the thing up correctly again. Surprisingly, the boiler internally was pretty clean!

 

Reassembled and using an online wiring diagram, managed to not blow it up. Pulled two cups since.

 

The first was 17g in 38g out so not far off the mark (that was 40 seconds though so perhaps I am getting enough in 30-35 seconds.

 

The second was 16g in and 40 out with a slightly coarser grind so with a little tweaking, I think I will get to where I need to be. Fingers crossed. Only cost me almost a full 250g of beans. Ha.

 

Experiments continue tomorrow. Thank you for all your help so far.

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Thank you but I don't actually know seeing I bought it used.

 

Some good news though, I managed to wire the thing up correctly again. Surprisingly, the boiler internally was pretty clean!

 

Reassembled and using an online wiring diagram, managed to not blow it up. Pulled two cups since.

 

The first was 17g in 38g out so not far off the mark (that was 40 seconds though so perhaps I am getting enough in 30-35 seconds.

 

The second was 16g in and 40 out with a slightly coarser grind so with a little tweaking, I think I will get to where I need to be. Fingers crossed. Only cost me almost a full 250g of beans. Ha.

 

Experiments continue tomorrow. Thank you for all your help so far.

There should be a label on the underside of the machine that'll give you the age.

Glad you got it goinf again. It can be a bit tricky following the wiring diagram especially at the switches.


Laissez les bons temps rouler

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There should be a label on the underside of the machine that'll give you the age.

Glad you got it goinf again. It can be a bit tricky following the wiring diagram especially at the switches.

 

Ah cool, I will check the bottom of the machine and see.

 

Ha, it was intimidating at first with wires everywhere but it was quite logical following the diagram.

 

Just brewed again this morning. 15g in, 34 out in 35 seconds. Getting more consistent. Will adjust the grind a little finer tomorrow to see what happens.

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Thank you but I don't actually know seeing I bought it used.

 

Some good news though, I managed to wire the thing up correctly again. Surprisingly, the boiler internally was pretty clean!

 

Reassembled and using an online wiring diagram, managed to not blow it up. Pulled two cups since.

 

The first was 17g in 38g out so not far off the mark (that was 40 seconds though so perhaps I am getting enough in 30-35 seconds.

 

The second was 16g in and 40 out with a slightly coarser grind so with a little tweaking, I think I will get to where I need to be. Fingers crossed. Only cost me almost a full 250g of beans. Ha.

 

Experiments continue tomorrow. Thank you for all your help so far.

 

Hi , dont force yourself into a narrow window of 1:2 in x time frame

How did the shots taste that you made ?


I write a blog, it's nothing to do with coffee ...

https://rjwinc.wordpress.com

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Hi , dont force yourself into a narrow window of 1:2 in x time frame

How did the shots taste that you made ?

 

Yes, I won't be so precise in future. Just being fairly consistent is nice at the moment. The last one yesterday and today were very nice from what I could tell. Have a little bit of a cold hanging oat the moment but not a million miles away from what I would expect.

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Yes, I won't be so precise in future. Just being fairly consistent is nice at the moment. The last one yesterday and today were very nice from what I could tell. Have a little bit of a cold hanging oat the moment but not a million miles away from what I would expect.

 

why do you keep changing your dose?

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Seems that about four other people since my post have recommended checking and cleaning the three-way valve - so at least you can see its a well-known issue! Don't forget to get a seal kit and also clean the boiler, if you do find partial blockage in the passageways of this little casting.

A good diagnostic that I use is to run the machine with this pressure measuring portafilter attached. See photo. It uses 4mm bore tubing and has an adjustable needle valve in he line. This is set to bleed 1ml/second and I run a 30 second shot with it and look for an even brew pressure, without any surges. With this set up you are reading actual brew pressure, not blind basket pressure, so 9bar is a useful set point. You can build this yourself for around £30-£40, from eBay parts and it has ongoing usefulness.

IMG_1373.jpg

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When you say you bought some fresh beans from your local shop, left the grinder set the same, and pulled a good shot.. The chances are that if it was right for these beans you hadn’t got it set right for the previous ones as all beans will need a bit different grind setting and some a lot different.

 

id stick with one bean type, buy a kilo minimum and stick with them, and dose the same amount every time.

 

If someone lives close by perhaps they would be willing to have a look?


____________

 

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why do you keep changing your dose?

 

Just going to try some fine adjustments to learn what works and what doesn't, that's all.

 

Seems that about four other people since my post have recommended checking and cleaning the three-way valve - so at least you can see its a well-known issue! Don't forget to get a seal kit and also clean the boiler, if you do find partial blockage in the passageways of this little casting.

A good diagnostic that I use is to run the machine with this pressure measuring portafilter attached. See photo. It uses 4mm bore tubing and has an adjustable needle valve in he line. This is set to bleed 1ml/second and I run a 30 second shot with it and look for an even brew pressure, without any surges. With this set up you are reading actual brew pressure, not blind basket pressure, so 9bar is a useful set point. You can build this yourself for around £30-£40, from eBay parts and it has ongoing usefulness.

[ATTACH=CONFIG]38117[/ATTACH]

 

Thanks for that info! :)

 

When you say you bought some fresh beans from your local shop, left the grinder set the same, and pulled a good shot.. The chances are that if it was right for these beans you hadn’t got it set right for the previous ones as all beans will need a bit different grind setting and some a lot different.

 

id stick with one bean type, buy a kilo minimum and stick with them, and dose the same amount every time.

 

If someone lives close by perhaps they would be willing to have a look?

 

Yeah I know, hadn't used it for a while. I am doing what you say and going to stick with the ones I just bought for the foreseeable.

 

I also bought some for my Aeropress which I use daily at work with a hand grinder and that's lovely. :)

 

I think it seems to be pretty consistent now with pulling similar shots so will just continue to try and experiment.

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This might sound daft but I was having problems with my gaggia, first shot always fine second one hardly anything would come out. I found that because I was washing the portafilter after the first shot when the next grind went in it must have mixed with any left over water from the washing and caused it too block because when I cleaned it then dried with kitchen roll the second shot came out perfect. Still new to this and don’t know what proper procedure is with you professionals but I know don’t wash the port filter between shots and everything’s fine.


Gaggia classic, Eureka Mignon

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Posted (edited)
This might sound daft but I was having problems with my gaggia, first shot always fine second one hardly anything would come out. I found that because I was washing the portafilter after the first shot when the next grind went in it must have mixed with any left over water from the washing and caused it too block because when I cleaned it then dried with kitchen roll the second shot came out perfect. Still new to this and don’t know what proper procedure is with you professionals but I know don’t wash the port filter between shots and everything’s fine.
Its ok to wash pf just make sure its perfectly dry before adding the ground coffee as you have found out

My procedure is, not that I'm a pro, is to make a shot, empty pf basket, wash it, dry it, clean inside group head with water before replacing pf to warm ready for the next shot.

Hope that helps

Edited by MinesAbeer

It doesn't matter how you get there it's only the end result that matters

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Posted (edited)

Heres how the pros do it.....

Nice video @DavecUK keep them coming

Edited by MinesAbeer

It doesn't matter how you get there it's only the end result that matters

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Hello there. This is my first post after much browsing and reading. Hope you don't mind getting straight down to my problem?

 

I bought a used Gaggia Classic about 18 months ago and have always had issues despite the previous owner having none whatsoever. The main issue is, often I will get nothing from the machine but a few drips of coffee. Every now and then I will get a good pull in around 35-40 seconds which tastes fine so I keep all my grind settings identical and then the next time, nothing or just a few drips. This happened again yesterday.

 

Spoke to a very helpful chap in my local shop, bought some Deerhunter beans (fresh) left my grinder on it's previous setting but this time did as he said and used 18g like they do in the shop. In 35 seconds, I had a delicious coffee. Nailed it, I thought. Next time, same settings, same tamping, nothing. Tried again, nothing. Left it until today again again, nothing but a few drips.

 

SO I have now cleaned, backflushed, descaled, tested flow rate 300ml in 30 seconds, cleaned behind the shower screen and the thingy behind that and low and behold, exactly the same. Tried different grind settings on the Smart Grinder Pro, different weights of coffee from 14-18g and very inconsistent. At anything from 16-18g, the puck seems to be hitting the screw in the centre of the screen which is why I tried a little less.

 

The last settings I tried was 14g at a 22 setting on the grinder and managed just short of a double shot in 40 seconds but it didn't taste great.

 

I would LOVE some advice from you experienced folks and look forward to reading any replies.

 

Many thanks.

 

I welcome any advice anyone can give with this because I just want to be able to pull consistent coffee.

 

I used to get this by putting too much grind into the PF then tamping it to hard. It would clog the machine.

 

Even now sometimes I only get a small trickle out of just one of the PF outlets and have to run it for 5 mins to get a cup... it just seems to be a thing with these machines, I figure they are low output with a small boiler.


 

 

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Just want to come back to this as it has been a while and I didn't acknowledge the last few responses. 

 

After having a few good cups, I am back to square one. Same beans, same grind, then boom, nothing but a few drips from the PF. 

Wasting so many beans trying to get a decent coffee from this machine, it surely shouldn't be this hard. Cleaned everything several times and the water flow rate seems good with no PF/basket (600ml/min) so I have no idea where I am going wrong and I am on the verge of throwing the thing out!

Anyone want a free Gaggia classic?

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