# gaggia classic low flow problem



## thomasn75

hi all

hope you can help as i have run out of ideas. i have used this forum to try and fix my problem but have failed so far hence this post. i have a gaggia classic which until recently worked well. i descaled it 3 weeks ago with official descaler liquid. ok after. then went on holiday for a week and when i came back the flow through the group head just got worse and worse where now i have very little flow. steam through steam wand ok but i cant get water flow out of it as described in the instructions(on and steam valve open and pump on) only get intermittent steam so this is what i have done:


suspecting the solonoid was blocked took gaggia apart and cleaned it all - no fix

replaced solonoid as couldn't hear click - no fix - need to double check click tonight with chopstick as suggested somewhere on here. i don't have a multi-meter to check electrics.

took is all apart again and cleaned all and blew air through all holes and water with good flow(incl OPV valve). - no fix

soaked OPV valve and base of boiler in descaler - no benefit.

then i started to wonder if the pump was working or an airlock. pump is running. unscrewed hose to OPV and water being pumped out. then tried the turkey baster injecting water into hose into pump - no benefit.

then let pump drain water from turkey baster and kept topping it up( holding it above pump. it sucks water in but not much comes out the other end - a few drips from group head and intermittent steam ( with power on, pump on, steam of and steam wand valve open) kept it running for 2 min but pump was getting hot so switched it off to cold down.


the whole unit, boiler is in good condition and i have run out of ideas and i dont want to spend anymore money unless i can figure out whats wrong. i am hoping someone has some ideas.

thanks

thomas


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## Syenitic

Have you removed the shower screen to check the state of that and the block behind it. Mine was once all gunged up with coffee muck and had a reduced flow as a consequence?


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## russe11

possibly you have by descaling it dislodged some scale and it has blocked itself, more or less back to where you began when you first descaled!

Have you back flushed using a blank filter basket (no holes) with something like Puly Caff which is a detergent that breaks up coffee oils internally that build up over time i.e. inside your 3 way valve. This needs to be done fairly regularly, you can also soak your shower screen and baskets and bits n bobs like that.

When you descaled did you let it sit (switched off) for 20 mins then give it a burst through with water, then let it sit again and so on?

Sorry if I'm repeating all you have done already...

Did you run machine without screen and carrier/dispersion plate, remove this with with 2 allan keys? This allows it to flow a bit better in case it is thick with coffee oils. All these parts need inspecting to see if they are blocked.


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## thomasn75

sorry forgot to say that i have got shower screen off as it is somewhat caked with coffee so testing machine without it on as soaking it hasn't cleared it. i think i will have to sit with a needle and unblock holes. the boiler has been out twice and i have had block and shower screen off and some water coming out of the pinhole at the base of boiler with pump on. that's why i cant understand whats wrong. i have not done it since last descale yesterday so will try that when i get home.


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## Syenitic

Soaking in just water is unlikely to be of much use. I know this might raise some eyebrows here, but when I went to clean up my screen and plate I used a solution of Sodium Hydroxide or caustic soda on the screen (soaked it overnight). The chemical bath brought the screen up like new from a dire almost completely blocked state where only a few sprites of water were making it through from the pump. I think you should probably avoid prodding with a needle, but lets see what other folk think on that one.

I used a flat bladed screw driver and bamboo skewers on the plate to manually clear the gunk from there.

I didn't go any further inside than that.

I have since acquired a tub of Urnex Cafiza (same as Puly Cafe I think) and a blind portafilter basket to back flush to prevent that happening again.


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## russe11

Don't use a needle. Use some fairy liquid and a nail brush or a Syenitic said use something that will cut the grease that sounds as thou has built up.

There are 4 little holes as well on the dispersion plate that will have probably blocked. I use a toothpick or small blunt screwdriver to get in those. Also stick something that will not snap into the water hole in group head... give it a waggle as water is coming through, that sometimes help shift things. A straightened paper clip or similar.


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## Jumbo Ratty

Syenitic said:


> I have since acquired a tub of Urnex Cafiza (same as Puly Cafe I think) and a blind portafilter basket to back flush to prevent that happening again.


Exactly this.

Have you got a blind basket? have you ever backflushed it ?


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## El carajillo

From your first post did you actually completely dismantle the solenoid valve (including the large 19 mm nut) and examine and thoroughly clean the internals ?? The ports / orifice's inside are tiny and as Russell said a particle of scale could be partially blocking the waterway. As the ports are so small and it works under high pressure, just blowing through it does nothing at all.


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## thomasn75

right i am am back and thanks for all the advice. after doing some further tests the problem seems to have been that i pushed the hose to far down into water tank and maybe causes a slight kink. the pressure is improved but not perfect. i think i will have to change pump at some stage as i think it is getting worn out.

regarding the basket and screen i put it in dishwasher and scrubbed it with a washing up brush at it has got rid of alot of the blocked holes. will run it though again. i have never back flushed and dont really know what that is. is there a quick tutorial on here somewhere. i have only used the official gaggia liquid discaler for cleaning my machine.

also to confirm the whole boiler has been out. solonoid changed for a new one and OPV soaked in descaler. all the group head taken apart and descaled. boiler cleaned inside. all in all machine is good order(considering it was an ebay purchase a year ago). i think i need to set reminders for descaling more frequently and learn about this back flush.


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## Syenitic

thomasn75 said:


> ......... i think i need to set reminders for descaling more frequently and learn about this back flush.


Quite a few threads discussing the whys of back flushing. e.g.

http://coffeeforums.co.uk/showthread.php?15637-Why-Backflush-Gaggia-Classic

and how its done...






Note there has also been some dissent on here about whether backflushing should be done at all, based on the actual construction of the machine. This seems to be concerns re. less substantial components being put at risk. Try to figure out where your machine sits in the overall scheme (mainly its age; older=safer) and use that as a basis to proceed or not. Maybe someone with a better knowledge here will jump in?


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## Jumbo Ratty

OK, you really need to back flush your machine. I believe it will sort your problem out.It is something that should be done regularly. I do it weekly.

you will need Urnex Cafiza and a blank basket. Links provided, if you can find it cheaper well done.

http://www.ebay.co.uk/itm/Urnex-Cafiza-2-Coffee-Cleaning-Powder-900-g-New-/141751238250?hash=item2101083e6a

http://www.ebay.co.uk/itm/281705392845?_trksid=p2057872.m2749.l2649&var=580711411113&ssPageName=STRK%3AMEBIDX%3AIT

Also here is a guide to backflushing


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## thomasn75

great i have ordered those 2 bits and will have a go at this. again thanks for all the help.


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## El carajillo

Looks like you have covered all the bases thomas:good:


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## thomasn75

so just to finish this tread. i have now backflushed machine which did indeed clean out some gunk. but flow was still not great. i ordered a new pump and replaced it and the machine is now great again. thanks for all the help


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## les24preludes

I looked up this thread as a result of having a low flow issue. Mine is actually a Baby but an early 2002 one, very like the Classic internally. I took off the shower screen and group head to no avail, at this point just getting drips. Having nothing to lose I put a very concentrated mixture of citric acid and hot water into the tank and thankfully the drips started to increase and turn brown, followed by a small flow and then a nice robust flow. Put is all back together again, ran around 3 litres of clean water through the machine and it's working fine again. Possibly a narrow escape. A reminder to clean more regularly in my case - left it for a good 6 months over the summer period.


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