# Normal group head flow on a gaggia classic?



## lnw06

Hi all. I am new to the forum and am new to making espresso....

I recently purchased a 2007 gaggia Classic on eBay (£50!!) with a flow issue.

Before using it I have followed the threads and stripped it , cleaned the solenoid, replaced the gasket and cleaned the shower plate. None of it was scaly or blocked.

I have yet to attempt an espresso ( tonight's test).

I back flushed and rescaled with stuff I bought from happy donkey and just wondered what the normal flow should look like out of a shower head?

The first time it looked just like a normal shower, then after back flushing the flow rate seems quite fast but it doesn't sprinkle it is just one or two main parts that flow?- is this normal?

Does this sound like a problem with the pressure IE OPV? - I didn't remove or touch this when I cleaned the solenoid?

Any help appreciated- also what are the two rubber tubes in the water tank- one for the group head and one for the steamer?

Thanks in advance!!

Luke


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## hotmetal

The tubes are 'out' and 'return', like arteries and veins. Anything coming back from the OPV goes back into the tank. (I am 99% sure.) You only have one boiler that feeds the group and steam wand.


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## froggystyle

Pull a shot and see how it runs i would suggest


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## Jumbo Ratty

Without knowing if the OPV mod has been done on either your machine or the one in this clip.

So lets assume the one in the clip is at 15 bar pressure, came to this conclusion because the flow rate seems pretty full on.

Compare yours to it, see what you think. But the main proof will be in the pudding, see how your machine makes a coffee, it may be OK

If it does seem too low maybe the OPV mod has been done by someone incompetent and it might be set below 9 bar? just a thought.

[video=youtube;aUke3h-HyyU]


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## lnw06

Wow talk about speedy service! Thanks guys will try tonight and let you know!


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## Jumbo Ratty

Just to let you know I have conducted a comparison with my machine and the one in the video.

They appear to be both about the same flow rate. My machine is factory set at 15 bar, I'm the only owner of my machine so I know it hasnt been adjusted.


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## froggystyle

So why have you not changed it yet to 9 bar?


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## jeebsy

froggystyle said:


> So why have you not changed it yet to 9 bar?





> Un-Modded Gaggia Classic 2014 and proud


^


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## froggystyle

Yeah, but why, makes no sense to go against everything else on the market, unless you buy a delonghi of course.


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## Jumbo Ratty

Just keeping my options open incase I ever wish to use coffee pods


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## Mrboots2u

Jumbo Ratty said:


> Just keeping my options open incase I ever wish to use coffee pods


Cheaper then italian job ?


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## froggystyle

Jumbo Ratty said:


> Just keeping my options open incase I ever wish to use coffee pods


Fair enough, but i reckon i would just buy a crappy argos/tesco machine for that, would using a classic make much difference on pods?


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## jeebsy

The benefits of the OPV mod are probably negligible if you're using (pre-ground?) Lavazza anyway


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## lnw06

So if I did decide to alter the OPV back- is it easy to know which way to adjust it- I think there are a few posts on the subject, the flow rate is fast it can fill a mug in 60 seconds and the wiring inside has been labelled with tape indicating someone has been in there . I will make an espresso and let you know. A bit nervous about adjusting the OPV though


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## Jumbo Ratty

the 3kgs we got from Lidl are lavAzza beans not pre ground


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## jeebsy

Hence the question mark, but the wider point still stands


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## Jumbo Ratty

lnw06 said:


> So if I did decide to alter the OPV back- is it easy to know which way to adjust it- I think there are a few posts on the subject, the flow rate is fast it can fill a mug in 60 seconds and the wiring inside has been labelled with tape indicating someone has been in there . I will make an espresso and let you know. A bit nervous about adjusting the OPV though


Doesnt sound that fast a flowrate unless its a massive mug

People may want to know the capacity of the mug.

You will need a gauge readily available on the forums here to adjust the OPV properly


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## lnw06

Probably a 300ml mug...


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## lnw06

I think!


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## froggystyle

Big then...

Just pull a shot and time 30g out.

What grinder, beans are you using, have you a better tamper than the plastickkkky thing gaggia give you with the machine?


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## Jumbo Ratty

*lnw06*

if you have a measuring jug time exactly how long it takes to fill exactly 100milliliters,,, if you do this I will do the same and then you will be able to tell whether your machine is running at *15 bar pressure* do this without the portafilter in situation.

Im about to have lunch now so will be back shortly to see if you can do this

* im assuming pressure will affect the flowrate*


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## lnw06

Yes got an58mm Tamper from happy donkey and a naked PF


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## lnw06

Excellent will do but I am at work until this evening but will do that and post back- really appreciate the help!


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## Jumbo Ratty

OK,,, I timed some running times. These are all timed from when the switch was switched on to off and without the portafilter in place and when the light indicated it had reached the required temperature.

I found a few variations though, the first timed run was 100mls in 15 seconds. This was the first timed run from the machine being turned on and ready to roll and took a few seconds for the water to appear after flicking the switch

I did a second timed run of 200mls to check the time and it was in 20 seconds, the water appeared immediately this time.

I waited a while and did a third, again the water was immediate and 200mls took 20 seconds.

After now timing about 5 separate 200mls im happy to report 20 to 21 seconds being the time taken, I opted for 200mls as it was easier to see the level in my jug.


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## froggystyle

Here is an idea, buy the parts to do the mod, leave the machine at 15 bar for a few weeks, then do the mod and then see if you can notice any difference in your shots.

Costs less than £10.


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## lnw06

Ok so I also did 200mls and mine consistently took between 22-23 seconds. Interestingly on the third go there was more of a shower like appearance from the shower screen.


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## lnw06

A 60ml espresso with 18g took 15 seconds-'if that helps? A good shot is supposed to take 25 seconds isn't it?


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## jeebsy

lnw06 said:


> A 60ml espresso with 18g took 15 seconds-'if that helps? A good shot is supposed to take 25 seconds isn't it?


You control that with you grind


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## lnw06

Yes-so sounds like the pressure/ flow issue is fine and my wife won't kill me for "buying a broken machine and what's wrong with instant anyway" then.......? Now to just practice at tamping, frothing and grinding.........


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## jeebsy

What grinder are you using?


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## Jumbo Ratty

lnw06 said:


> A 60ml espresso with 18g took 15 seconds-'if that helps? A good shot is supposed to take 25 seconds isn't it?


you control that with you tamp pressure


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## lnw06

Sage smart grinder....... Pretty new to this- it is becoming addictive ......


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## froggystyle

So have you pulled a shot yet, with actual grinds??


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## lnw06

Yes. Seems to be working fine just my unskilled hands need to work in the grind to go from 15 seconds to 25 seconds! It's all good fun


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## froggystyle

take your grinder to zero, then wind it back slightly, this will more than likely choke the classic, but it will show if you have the version with the shims that make it grind fine enough for espresso.

What beans are you using?


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## lnw06

Locally bought beans. What's the shims?


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## froggystyle

the first release of that rinder struggled to get the grinds fine enough for espresso, so they released a version with shims in it to bring the burrs closer, i think you can request them from sage if its an ealrier version.

When did you get it and was it new/2nd hand?


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## lnw06

Second hand it's model number BCG820BSS. Not sure of the year - think it might be 2014......


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## froggystyle

You might be ok then, think they made the change 2012/2013

Sure you know this, but tamp consistently and not to hard, loosen your grind till you hit the 30 seconds mark, doesn't have to bang on 30 seconds, anywhere from 25-45 depending on your input weight will be fine for starters.

Are you using the classic right in terms of temp surfing?


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## lnw06

Well I've read some posts but not attempted yet- I am getting a bit confused with the light on the right going on/ off and when is good to brew and not?


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## froggystyle

Turn it on, leave it for at least 20 minutes to warm ccompletly up, keep your cups on the top to warm them also and your portafilter in place.

Then, after 20 minutes you need to get your grinds in your basket and tamped, lock your PF in place and watch the lights, when the light on the right goes out, it means the boiler temp has dropped and the element has kicked in, when it comes back on it meeans the boiler is up to temp and is ready, at this point pull your shot.

Some say do a flush, give the steam wand a flush... whatever, i found the best results with my machine was to wait a second or two after the light comes on then hit the brew switch.

Are you doing milk alsa, are you making two shots at a timee, say for you and someone else in the house?


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## lnw06

No it's just me and the plastic but on the wand shot off when I purged it! So I think I'll invest in one of the rancilio wands!


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## froggystyle

wise investment if you want to add milk to your drinks, the standard one fitted is next to useless...


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## lnw06

Thanks for all your help. Will be onto happy donkey in the morning!


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## froggystyle

Pick up a naked portafilter if you don't already have one, helps show what your distribution is doing...


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## lnw06

Got one!


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## risky

I'm interested to see the pressure rating on mine once I get the gauge from the pay it forward. Mine looks nothing like the video on the first page but I have an IMS Screen so not sure how much that would affect how it looks. Previous owner had not done the OPV mod so unless someone before him did it I may have a problem...


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## lnw06

Sounds interesting. Let me know what it is.......


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