# Backflushing and bigger solenoid



## ItalianBrew (Feb 15, 2016)

Right so, need a couple of things clearing in the old brain pan about my Gaggia Classic please folk.

Back flushing, is it really necessary to do that, wont it force crap into the solenoid and end up blocking it!?

This takes me to the next thing, the solenoid, mine is still the original solenoid, where do we source the upgrade larger solenoid and does any one have any idea how much they are!?


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## StuartS (Jan 2, 2015)

Not if you use pulycaf or cafiza - removes the coffee oils which would clog things up eventually.

Don't know about sourcing the larger valve.


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## Jumbo Ratty (Jan 12, 2015)

Backflushing is important.

Why are there blank baskets and special backflushing powder on the market otherwise ?

The video below explains why and how it should be done

The larger solenoid.

it can be bought from MrBean2Cup and from Ebay, both links below.

Put me off slightly that you are meant to take your boiler off and strip it for a deep clean prior to fitting it.

Also the price, nearly 33% of what a second hand machine would cost.

Also, it wont improve the coffee taste and doesn't guarantee it wont block up still.

I can take my solenoid valve off, clean it and have it back on in under 15 minutes.

Please note: You must take the boiler apart and clean it manually prior to installing this solenoid valve (full service). Otherwise the solenoid valve can be damaged/blocked very soon.

Replacing the solenoid valve would only solve a symptom, not the problem, unless it is an electrical fault to be blamed.

http://www.gaggia-parts.co.uk/Gaggia-Classic-Solenoid-Valve

http://www.ebay.co.uk/itm/Gaggia-Classic-Baby-Replacement-Solenoid-Valve-CEME-Olab-Parker-DM1645-001-/161325985908?hash=item258fc73074:g:EwUAAOSwr81UTOuM


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## ItalianBrew (Feb 15, 2016)

Appreciate the well thought out and helpful response Jumbo Ratty, thank you.









That was the exact same video I watched about back flushing but then I read a comment about back flushing forcing scale and grounds into the original solenoid causing them to be blocked and I got all panicky as I haven't got the bigger solenoid. Yeah, £40+ for the solenoid is a bit up there as all I should do is remove the solenoid and clean it like you do, have to find a youtube about doing that and I'll get the blank basket and the detergent asap, something is really not right with my little Gaggia, it's having a mare of a time making coffee, I've made sure I don't over fill the basket, I don't tamp too firmly, I always prep the pump, I've used a de-scaler to get any scale out and still it is struggling, I've done the shower head and group head removal and cleaned those up nicely, going to have to hope the back flush improves things a little.


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## Jumbo Ratty (Jan 12, 2015)

I reckon it'll be your solenoid. Especially if you've recently done a descale.

If you hit both the steam switch and espresso switch and turn the steam wand (have a jug under the spout, water will come squirting out) on does the pump make the correct sound?

Turn the switches off, turn the steam knob off.

Now hit the espresso switch on its own, does the pump make the right noise for a brief half second or less and then sound dull, like its laboring?


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## shaunclarke (Nov 30, 2011)

When I brought my 2008 Classic it had never been back flushed. I got the blanking plate and used Pulycaff and what came out was like black sludge. I removed (and replaced) the shower screen and the dispersion block and soaked that in Pulycaff to clean it up. I now back flush once a week and it keeps my Classic lovely and fresh.


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## ItalianBrew (Feb 15, 2016)

Jumbo Ratty, this is the first time I have owned a machine like this, I have absolutely no idea what it is supposed to sound like so cannot tell you if it sounds right or not.

Nadgers, did the back flush today and guess what, our Gordon kept this baby in tip top shape, hardly a smear of coffee brown in the white stuff when it came out.


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## gaggiamanualservice.com (Dec 22, 2009)

there is a link on the wiki page that I did to explain how to check and clean solenoid, if you cant find it I have the link on my website http://coffeeforums.co.uk/showthread.php?3334-How-to-check-if-the-solenoid-is-blocked

I do the larger solenoid for £39.50 plus post if interested


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## Jumbo Ratty (Jan 12, 2015)

Jumbo Ratty said:


> I reckon it'll be your solenoid. Especially if you've recently done a descale.
> 
> 1. If you hit both the steam switch and espresso switch and turn the steam wand (have a jug under the spout, water will come squirting out) on does the pump make the correct sound?
> 
> ...





ItalianBrew said:


> Jumbo Ratty, this is the first time I have owned a machine like this, I have absolutely *no idea what it is supposed to sound like *so cannot tell you if it sounds right or not.


Do this without the portafilter in the group

Still follow the procedure ive described above, but instead of listening for the correct sound make a mental note of how the pump sounds when you are running water out through your steam arm as described in part 1.

Then do part 2. of the procedure.

Does the pump make the same noise when trying to run water out of the group head for about half a second and then sound muffled, much quieter?


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## ItalianBrew (Feb 15, 2016)

Jumbo Ratty said:


> Do this without the portafilter in the group
> 
> Still follow the procedure ive described above, but instead of listening for the correct sound make a mental note of how the pump sounds when you are running water out through your steam arm as described in part 1.
> 
> ...


Okay, I followed your instructions to the letter, the machine sounds a lot more 'rattly' with the water going through the wand, goes from a rattly uuuuuuurrrrrrr to less rattly uuuuunnnnn, so I am guessing the pump is okay.

There is not very much water making it through the group head though 4 drips with intervals of at least .5 seconds, it takes ages for the water to come through with the portafilter and grounds, easily coming on to 2 minutes.


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## Jumbo Ratty (Jan 12, 2015)

sounds like the pump is OK. one thing less to concern yourself with. But does sound like its the solenoid more than ever

Assuming you have taken the shower screen and dispersion block off and cleaned those. What were they like ? clean or very mucky when you took them off?

Also, have you descaled it? If so did you let the descaling solution out through the steam wand or the group head?

I still reckon its the solenoid valve blocked with scale.


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## ItalianBrew (Feb 15, 2016)

Jumbo Ratty said:


> sounds like the pump is OK. one thing less to concern yourself with. But does sound like its the solenoid more than ever
> 
> Assuming you have taken the shower screen and dispersion block off and cleaned those. What were they like ? clean or very mucky when you took them off?
> 
> ...


The block was not too bad although the four holes were pretty much closed up with oily black stuff which I cleaned thoroughly, the shower screen could probably do with replacing, I will take the solenoid off again and see if there is anything in there.

Thank you so much for helping me get this sorted, I'm half expecting to have to go back to using my mokapot and tossing the Classic, not a happy thought.


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## Missy (Mar 9, 2016)

ItalianBrew said:


> I'm half expecting to have to go back to using my mokapot and tossing the Classic, not a happy thought.


Can't imagine theres much on a classic that cant be fixed with some elbow grease.


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## Jumbo Ratty (Jan 12, 2015)

what I do when i get the solenoid off and before its dismantled is whack it into the palm of my hand so that the two holes with the rubber washers hit my palm, i then feel the water that has come out,, i can sometimes feel and see the pesky scale.

Also, when i have dismantled it the main hole im concerned about it the smallest one thats exposed when the spring piston is removed. Go in from that hole with the pin. Then cover the exit hole with the rubber washer that isnt connected to that hole and fill the top part with some water then blow it through again into the palm of your hand,, see if you can then feel any particles of scale.

btw, you didnt answer about the descaling question?


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## ItalianBrew (Feb 15, 2016)

I did de scale it and I ran it through the steam wand as well as the group head.

Just had the solenoid off and WHOA, the outlet hole was chocked full of small scale sheets, there wasn't anything there before, cleaned it all out and put it all back together, turned on the machine and nothing, zilch, not even a drop of water, took off the solenoid again and it's blocked even worse this time, I'm guessing this means the boiler is heavily scaled!?

What descaler do you recommend, I used some of that OUST but clearly it didn't work very well, should I remove the boiler to get it fully descaled?


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## Jumbo Ratty (Jan 12, 2015)

this is what i thought was happening.

You need to descale it again, i just use citric acid descaler i bought from wilcos. you might even need to descale it 2 times on the trot.

when you are descaling you are not meant to run the water out the group head, just the wand.

I would be inclined to fill the water reservoir and let a lot of water out through the steam wand, the broken fragments of scale could exit that way

Alternatively, you can keep putting the solenoid back on, letting it fill with scale and remove it, clean it put it back on and keep repeating that until all the broken fragments of scale have been removed. I know this may sound like a long winded procedure but thinks about 10 times might do it. But if you decide to do this then let the machine labour for a while so that as much scale is in the solenoid as possible.


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## timmyjj21 (May 10, 2015)

I use basic food grade citric acid, but any descaler will react with the aluminim boiler if left for a long period so care should be taken.

If you have the DIY capability, I would open up the boiler. If the boiler had fluffy white stuff at the join between aluminium upper and chromed brass lower, then the seal is blown and should be replaced anyway. I use a dremel and brass brush to clean out the scale inside, freshen up the boiler face if needed with fine wet and dry sandpaper on a perfectly flat stone kitchen bench top. Then replace the seal.


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## ItalianBrew (Feb 15, 2016)

Nadgers, no descaler in the village shop so have to wait for some to be delivered next week.

If the descaling doesn't solve the problem I shall try the dismantling of the boiler, not overly keen on doing that, I don't have many tools to hand and I'm very nervous of breaking it, so for the time being it's back to the Moka pot, very unhappy camper right here.


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## timmyjj21 (May 10, 2015)

The classics are pretty much unbreakable, however, opening up the boiler does have its risks, with the potential for corroded boiler bolts being impossible to remove without access to extra tools.


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## ItalianBrew (Feb 15, 2016)

Well don't that just about beat all, I just stripped down the boiler and found lots of beads of mineral deposits and a lot of flakes so cleaned that all out, removed every last trace of muck, re-checked the solenoid, everything clean and clear, re-build the pump, put it all back together and you'll never guess what, it made no difference what so ever, I'm totally lost and drinking Moka pot coffee now and it's nasty after the delights of Espresso, very gutted.


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## Glenn (Jun 14, 2008)

I have got some Gaggia descaler - popping a few sachets in the post for you tomorrow


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## brokentechie (Jun 17, 2015)

ItalianBrew said:


> Well don't that just about beat all, I just stripped down the boiler and found lots of beads of mineral deposits and a lot of flakes so cleaned that all out, removed every last trace of muck, re-checked the solenoid, everything clean and clear, re-build the pump, put it all back together and you'll never guess what, it made no difference what so ever, I'm totally lost and drinking Moka pot coffee now and it's nasty after the delights of Espresso, very gutted.


I think you definitely have some crap stuck in the solenoid, I *think* you can strip them down a little ways to soak in descaler and clean up with a fine pin.


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## ItalianBrew (Feb 15, 2016)

Glenn said:


> I have got some Gaggia descaler - popping a few sachets in the post for you tomorrow


Do you reckon some descaler will sort it then Glenn, I'm all stressed out worrying it's game over here, man I ain't gonna be able to stretch for buying another one for a long time, to say I'm pretty low about it right now is a vast understatement.


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## Glenn (Jun 14, 2008)

Worth a shot

There's probably crap in the places you cannot physically see

This is harsh stuff so will clear lots of it


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## ItalianBrew (Feb 15, 2016)

brokentechie said:


> I think you definitely have some crap stuck in the solenoid, I *think* you can strip them down a little ways to soak in descaler and clean up with a fine pin.


Where could it have come from though, I cleaned the solenoid again whilst I did the boiler, has the scale come from somewhere else, I'm very confused!


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## ItalianBrew (Feb 15, 2016)

Glenn said:


> Worth a shot
> 
> There's probably crap in the places you cannot physically see
> 
> This is harsh stuff so will clear lots of it


That's really cool of you to send me some Glenn, I appreciate it very much, thank you.


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## Glenn (Jun 14, 2008)

The postie will deliver some white powder to you so that you can feed your drug habit


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## brokentechie (Jun 17, 2015)

ItalianBrew said:


> Where could it have come from though, I cleaned the solenoid again whilst I did the boiler, has the scale come from somewhere else, I'm very confused!


It only takes a tiny (almost microscopic) amount of scale to block it up.

Any loose particles will potentially be shifted after manual cleaning of scale and can cause issue.


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## ItalianBrew (Feb 15, 2016)

Glenn said:


> The postie will deliver some white powder to you so that you can feed your drug habit


Ha-ha, some years ago perhaps Buddy but these days my habits are more on the green leafy side, yeah okay so green Bud side of things.


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## ItalianBrew (Feb 15, 2016)

WOOHOO, I have no idea how I did it but it's working now, I stripped down the solenoid again to check and it was perfectly clear, not even a dot of scale any where to be seen, so with a heavy heart I put it back together and put it back on the boiler, I was about to walk out of the kitchen and I had a weird urge to give it another try, see if the problem was still evident, would you Adam & Eve it, it is working perfectly now, must have been a bit of scale in a tube somewhere maybe, I have no idea but I am currently enjoying immensely a lovely Espresso, I'm super happy.


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## Missy (Mar 9, 2016)

Hurrah! Probably worth heeding Jumbo Ratty's suggestion that it may happen multiple times before it finally settles, especially if the boiler was as grim as it sounds! Bet that espresso tastes amazing!


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## timmyjj21 (May 10, 2015)

Nice! The solenoid can be a tricky one to get un-blocked


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## Jumbo Ratty (Jan 12, 2015)

Missy said:


> Hurrah! Probably worth heeding Jumbo Ratty's suggestion that it may happen multiple times before it finally settles, especially if the boiler was as grim as it sounds! Bet that espresso tastes amazing!


It might well happen again after just a few cups. I sometime think I sound like a scratched record ITS YOUR SOLENOID !!!

Enjoy you espresso in the meantime.

I think scale is my official nemesis


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