# Cherub - few technical questions



## coffeyanan (Sep 1, 2017)

Hi!

So I'm a new user of Fracino Cherub. If you followed my story you'll see that I have a cherub in a terrible state, but somewhat still functional. I'm just getting used to it these days, we'll see how it goes.

I have a few questions that I'm not getting quite right.

I need to change the group head seal since I can see this one is a bit torn and if I backflush it it drips a bit. So how do I know which thickness to get? (There are 8, 8.5 and 9mm) Is it really important?

Second question is about backflushing: I do it with a blank basket and leave the pump on for about 30 seconds. Where does this water goes when it hits the wall? How is this not harming the machine and the pump?

My last question (for now) is when descailing it (I found instructions here on this forum for cherub), the recipe reads taht it needs 50mg citric acid crystals per liter of water. What excactly are these citric acid crystals, since I'm not from UK and don't know what's it called arround here. If anyone could post a picture of the well known products that would be suitable.

Thanks for help!


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## 4515 (Jan 30, 2013)

Not sure on the thickness of the group seal but Fracino sell the seal and have worldwide distributors who may be able to assist

When you backflush the water will pressurise and then release into the drip tray when you switch off the pump - it wont damage the pump

Not sure about the citric acid but I'm sure someone will be along to advise


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## lake_m (Feb 4, 2017)

Where are you? Citric Acid is a very common descaling chemical and I would think it would be readily available everywhere.

Try Google to find the local equivalent.


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## coffeyanan (Sep 1, 2017)

working dog said:


> When you backflush the water will pressurise and then release into the drip tray when you switch off the pump


I think that at my machine it does not get released into drip tray as it does when making an espresso. Don't know what's the deal.

Fracino has on it's site listed as parts all these thicknesses, it seems it differs from depending on the model of cherub.


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## espressotechno (Apr 11, 2011)

If your Cherub is an old machine with a lot of past useage, then an 8.5mm E61 group seal will be a good fit.

If it's too thin, fit a cardboard spacer behind the new seal.

PS After fitting the new seal, you might as well fit a new shower screen at the same time.....


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## 4515 (Jan 30, 2013)

coffeyanan said:


> I think that at my machine it does not get released into drip tray as it does when making an espresso. Don't know what's the deal.
> 
> Fracino has on it's site listed as parts all these thicknesses, it seems it differs from depending on the model of cherub.


When you release the portafilter is there still pressure in there ?

It sounds strange as I'm sure that water vented on my Cherub when making coffee and backflushing. The only difference is higher pressure and no coffee in the blind filter.


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## espressotechno (Apr 11, 2011)

If there's pressure still in the PF on release, then the group solenoid valve isn't working correctly - probably bunged up with scale or coffee gunge.

Give the group a good backflushing with Pulycaff, then descaler, which should clean out the valve & get it working.


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## coffeyanan (Sep 1, 2017)

There is no pressure when I unlock the portafilter when making coffee and the valve on the bottom does release water after I turn off the pump. It's just on the backflush I don't think I see any water coming from valve, thats why I was wandering where it goes... I need to descale it anyway and change the group head seal. These seals are just put on arround the head right, there is nothing to glue or anything like that?


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## 4515 (Jan 30, 2013)

just remove the old one and push the new one on. No other fixing is needed


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## ajohn (Sep 23, 2017)

Fracino have a decent web page on the parts used in their machines. It's here

http://www.fracino.com/parts.html

What they don't have for some reason is somewhere to download the manuals that come with the machines. The Piccino one states the seal part number for the machine. Your probably would too.

One grouphead seal supplier states that an E61 8.5mm seal fits all Fracino machines.

Unless you have fluids gushing out of the group when the blank filter is in place the problem wont be the seal. I had a bit of this initially and it turned out to be lots of dried out coffee caked on and around the seal. It came out pretty easily via a group head brush. I then removed the shower screen and the bits behind them and soaked them for 20min in Puly in boiling water. Also used a bit of that on a rag to wipe round where the shower stuff sits.

I then back flushed it with Puly as directed on the package and that came out clean. It took a lot of flushing to get rid of the Puly. Tried to make a cup of coffee and it leaked again.







I'd put too much coffee in the basket.

John

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## coffeyanan (Sep 1, 2017)

I have to buy pulycaff. I saw that when I backflushed the other day some water did in fact came out of the release valve on the bottom. Probably ok.

Anyway, is there any special procedure regarding turning on the machine? I just add water to the tank and turn the switch on. Sometimes I release a little steam and that's it. Wait for it to heat up, release some water trough PF and I'm ready to go. Does this sound right?


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