# no flow from group head on my Classic



## megastream (Nov 10, 2012)

Hoping someone can help me out. Been getting worse over the last few weeks, the flow is almost nothing - a few drips every couple of seconds when coffee'd up. I've de- scaled with the stuff HappyDonkey sells and also completely stripped the unit down, there was hardly any scale inside and nothing blocked.

I did make a mistake and took apart the opv before i understood was this bit did, hence i've unscrewed it completely and removed the spring! DOh!

Anyway, have adjusted it so many times now with the inner nut screwed in and out, makes no change at all - still no pressure through head.

Does anyone have any suggestions, driving me mad! TIA John


----------



## ronsil (Mar 8, 2012)

Hi & welcome to the Forum.

Someone is asking a similar question on another thread - I suggested to read here:

http://coffeeforums.co.uk/showthread...ow-coffee-flow

It may not be the answer but it worked for me. I found the blockage in the heavy metal twin hole, connection between the solenoid & the boiler. Needs to be unbolted from the boiler (allen key) & soaked in puly or similar to clean through. Take care not to loose the 2 very small washers.


----------



## megastream (Nov 10, 2012)

Thanks I have just double checked and removed the solenoid valve again its 100% clean inside and no blockages, spring and piston moving freely.

Im wondering if its the electronic part of the solenoid that is faulty as I cant hear it click when I turn on the water to the head (pump starts, not even sure if I should hear this part click though!)


----------



## AndyL (Apr 10, 2011)

&



megastream said:


> I did make a mistake and took apart the opv before i understood was this bit did, hence i've unscrewed it completely and removed the spring! DOh!
> 
> Anyway, have adjusted it so many times now with the inner nut screwed in and out, makes no change at all - still no pressure through head.
> 
> Does anyone have any suggestions, driving me mad! TIA John


This sounds to me like it might have been your undoing. This valve controls the pressure to the group head if you made a mistake during the re-assembly or it is completely out then your pressure will have gone to pot.

Do you have access to a pressure gauge?

Check to see if you're getting water pumping back into the tank, this would indicate that the valve is either stuck open or not assembled correctly.

See here for a guide to OPV adjustment:

http://coffeeforums.co.uk/showthread.php?t=3859

Sent from my GT-I9300 using Tapatalk 2


----------



## megastream (Nov 10, 2012)

Thanks I've just posed on that thread to see if the loan scheme is still running.

About to click the order button on Amazon and get a new unit had no idea how much we rely on a nice latte!

If I were to take the opv off and apart and post a pic would someone be able to confirm if I've put it together correctly?

Feel a right wally taking it apart now!


----------



## AndyL (Apr 10, 2011)

I have never taken one right apart tbh,

(that would be silly.  ) and I did have a good search for you to see if I could find a picture or schematic but no joy. Hopefully someone else can help on that front.

I would take it apart and see if you've made an obvious mistake. Take a pic and lay the parts out how you have assembled them. Maybe we can work it out. There can't be much in it.

Sent from my GT-I9300 using Tapatalk 2


----------



## megastream (Nov 10, 2012)

<img%20src=%22http://farm9.staticflickr.com/8484/8175213536_c86ee1487a_c.jpg%22%20width=%22800%22%20height=%22600%22%20alt=%22DSC01203%22>][/URL]  

Ok - here's how I've got it assembled....


----------



## megastream (Nov 10, 2012)

I've answered my own question - just found a link showing this is how it goes together. http://www.ruizs.org/archives/46


----------



## AndyL (Apr 10, 2011)

Yes it looks right. Why don't you use the flow rate method to check the opv. This will get you ballpark. You should be seeing 120-125ml in 30 sec. If you can't get anywhere near that then we'll have to think again.

Do you own a back flush plate?

Sent from my GT-I9300 using Tapatalk 2


----------



## AndyL (Apr 10, 2011)

I'm adding this image for future reference:

Disassembled opv










Sent from my GT-I9300 using Tapatalk 2


----------



## megastream (Nov 10, 2012)

I don't have a back flush plate...

After taking the picture I put it back together and again ran through trying to pull coffee with a full head, making small adjustments to the OPV - each time nothing at all until the adjustment is almost screwed right down, and then I get a very slow drip that would take an age to fill a cup.

I can't say I hear any click when I press for coffee, would the symptoms I have point to a faulty solenoid? Is there any way of testing this part?

Thanks for the replies with help so far.


----------



## AndyL (Apr 10, 2011)

We need to do some tests in order to determine where the problem is. Lets start with the obvious and work through.

1/ Do you have good flow with no portafilter in place?

2/ When you have coffee in the portafilter and start the machine do you hear the pump, is the machine stalling?

If the answer is yes in both cases could it be simply that your grind is just way to fine?

3/ Have you ever backflushed your machine? No!

Ok so you need to get a blind filter and some PulyCaff in order to clean your machine properly. The fact you have never backflushed your machine suggests that over time you may have accumulated grinds and coffee oils between the brew head and three way valve.

4/ when you stop a shot do you hear the machine depressurise? Do you see the water emptying into your drip tray from the 3 way valve?

Lets leave it there for now until you give me some feedback

Sent from my GT-I9300 using Tapatalk 2


----------



## megastream (Nov 10, 2012)

Thanks - answers below...

1/ Do you have good flow with no portafilter in place?

Yes - seems to be fine without the portafilter, good flow of water through the shower head

2/ When you have coffee in the portafilter and start the machine do you hear the pump, is the machine stalling?

Yes the pump starts with the coffee in, not stalling but does sound like its 'straining' when the OPV is screwed right down (the only time I get so much as a drip out)

If the answer is yes in both cases could it be simply that your grind is just way to fine?

Always used the same coffee (and amount used) in the last 18 months

3/ Have you ever backflushed your machine? No!

I have stripped down the whole machine and cleaned it - there is no scale in the machine iners that I can see (even inside the body it's virtually calc free)

Ok so you need to get a blind filter and some PulyCaff in order to clean your machine properly. The fact you have never backflushed your machine suggests that over time you may have accumulated grinds and coffee oils between the brew head and three way valve.

4/ when you stop a shot do you hear the machine depressurise? Do you see the water emptying into your drip tray from the 3 way valve?

Yes I do get a 'squirt' of water from the water exhaust pipe into the drop tray when the brew switch is turned off


----------



## repeat (Nov 14, 2009)

sounds like the grind is too fine to me. Try making the grind course or hardly tamping at all. What happens?


----------



## AndyL (Apr 10, 2011)

"I have stripped down the whole machine and cleaned it - there is no scale in the machine iners that I can see (even inside the body it's virtually calc free)"

Yes but i'm not talking about scale i'm talking about scummy coffee oils and grinds. Descaler won't get rid of that.

Btw do you grind your own beans or are you buying pre-ground?

Sent from my GT-I9300 using Tapatalk 2


----------



## bronc (Dec 10, 2012)

I need some help opening the OPV.. The nut which is supposed to be unscrewed with a 5mm allen key is stuck. I was barely able to get it through half of the thread and now it's completely stuck 1cm from the top..


----------



## gaggiamanualservice.com (Dec 22, 2009)

dont open the opv, LEAVE ALONE, cause more issues, mail me your mobile, i will ring tomorrow and try to sort you, [email protected].

same goes to all gaggia manual owners, the opv on ALL the machines from viva to baby twin is factory set for a reason. any problems you have will not be caused by the opv unless blocked with scaled. always seek advice first

regards

mark


----------



## coffeechap (Apr 5, 2012)

Unfortunately he is in Bulgaria!


----------



## bronc (Dec 10, 2012)

Thanks, Mark! Unfortunately the harm is already done. The nut is stuck mid-way so now I can neither screw it back down nor unscrew it. I'll visit a friend tomorrow who has better tools than me and can help me. I opened it first because I thought that it was badly scaled but now I'm not sure what's the problem. It looks like it's the pump actually but I first need to sort out the OPV. Yikes!


----------

