# No Water from Group Head - Self Priming Valve Maybe?



## PaulN (Mar 10, 2011)

Hi All,

Been a long time but i finally had time to play with my Gaggia classic...... Stupidly Last time i used it I didn't descale (didn't need it at the time) and now it seems the machine is somewhat blocked.

Now the last few times I used it it needed priming as the pump was starved of water. Once primed it worked ok.... this time no water coming out the group head just back into the water tank via the return pipe.

Thinking i was clever i squeezed this pipe hope i could force the water through the group head and then it started leaking from the back right of the machine..... (I think the return pipe may have come off) Anyway I only had enough time to check the group head screen which was really blocked with scale....

My first port of call is opening the machine... making sure the return pipe in on and descale but ive read the the Self Priming Valve could be at fault....

Has anyone got any ideas?

Thanks

Paul


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## timmyjj21 (May 10, 2015)

There is no self priming valve in a Gaggias Classic. First point to look is under the shower screen and dispersion plate, as its probably glued and blocked with coffee oils. If you have issues with scale, second point to look would be the solenoid valve- back right of boiler, black box. Remove , disassemble and clean.


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## MrShades (Jul 29, 2009)

Open it up and check that the pipe is back on the OPV properly - it's only pushed on to the OPV as the pressure in that pipe is usually low. By squeezing it, you've increased the pressure in the pipe and chances are that it has 'popped off' (technical term!) the OPV nipple. Put it back on and don't do it again.

Now - test what's going on by opening the steam valve and then try pumping some water through. Do you get any water out of the steam wand?

I think that chances are that the solenoid valve is blocked - and needs stripping down and cleaning.... but it could also be scale behind the dispersion block, or scale blocking the solenoid valve.

If I were a gambling man (CFUK raffles and £66M lottery draws excepted) then I'd say it was the solenoid valve needing a good clean (Classics don't have self priming valves BTW).


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## PaulN (Mar 10, 2011)

Hi Guys,

Thanks for the advice..... got a spare hour to look at the machine!!! I had much more free time when i was married lol

Return pipe back on and then i descaled the machine... I also put some descaler in my blanked portafilter and ran it but no water going to the group head only back into the tank.

Left it for a day.... and the blanked portafilter was so crapped up!!! But the water still just went back into the tank.... I will remove the solenoid valve and give it a clean... i can hear it clicking so its not failed.

How long is it safe to leave descaler in the machine and tank?

Thanks

Paul


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## PaulN (Mar 10, 2011)

Ps if the dispersion plate is behind the shower screen, it really didnt want to come off when id taken the 2 socket head screws out???? Any ideas?

Ps Ill try the steam wand later..... what will that prove if it does / doesnt work?

Thanks again

Paul


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## Missy (Mar 9, 2016)

I stuffed an Alan key in the hole and jiggled. Took a bit of force but not too much and the dispersion plate came off (yes it is behind the shower head!) I just had to be a bit brave in my use of force.


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## timmyjj21 (May 10, 2015)

http://coffeeforums.co.uk/showthread.php?29000-Ten-year-old-Classic!/page2&highlight=Gaggia+dispersion

To save me typing it out again, this thread covers dispersion plate removal.

Be gentle with the descaler since acid and aluminium don't mix well, and you really should use a back flush detergent in the blank basket.

Water thought the stream wand helps diagnosis and checks the pump is actually working. Also used to help remove the descaler from the boiler since the steam outlet is right at the top.

When cleaning the solenoid it would be best to completely open it, remove the plunger, use a pin and wiggle it around the holes inside, and also descale it. The brass will tolerate descaler overnight.


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## PaulN (Mar 10, 2011)

timmyjj21 said:


> http://coffeeforums.co.uk/showthread.php?29000-Ten-year-old-Classic!/page2&highlight=Gaggia+dispersion
> 
> To save me typing it out again, this thread covers dispersion plate removal.
> 
> ...


Thanks for the post...... im going to read about removing the dispersion plate in a bit...

What did scare me was it would be ok to leave the descaler in over night...... Its been in since the weekend as upto until last night after testing the steam wand i had no way of draining the system.......

I hope ive not shagged it... Im guessing drain the De-Scaler put water in and run it through the steam wand asap.?

I think it all points to a blocked Solenoid valve with the steam wand working fine...... I cant believe how much crap/scale is coming out the machine though!!!!

Thanks

Paul


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## timmyjj21 (May 10, 2015)

Ah well, it will probably be fine as the dissolved scale would neutralise some of the acid. If it is really looking messy, and you are a keen DIY person, open up the boiler and have a look!


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