# Descaling a Cherub



## blockhead

Hi

Does anyone have a clear set of instructions for descaling a Cherub that they would recommend please. I have searched but thought someone might have a link to one that they used.

Thanks in advance


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## thenag

This was posted a while back for the Cherub and I saved it in Evernote. Apologies to the original poster, but I never kept their name to give them credit.

- Bring up to working temperature.

- Switch off, drain boiler by turning on hot water tap and letting it empty as much as possible

- Clean water tank out and fill with solution of 50gm citric acid crystals per litre of water.

- Allow boiler to fill up with this descaling solution and reach working temperature

- Draw water from grouphead and steam wand to get descaling solution in there

- Backflush

- Switch off and leave for 30 minutes

- Switch on and bring up to working temperature.

- Draw water and backflush again. Switch off and leave for another 15 minutes

- Bring back to working temperature

- Switch off and drain boiler

- Clean out tank again and re-fill with clean water

- Allow boiler to refill with clean water, then let machine come up to temperature

- Draw water through all exits - grouphead, steam wand, water tap.

- Switch off and empty boiler

- Repeat last three steps three or four times to get rid of all descaler in boiler

- Done


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## glevum

This is the exact instructions i have used last couple of years, works a treat


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## blockhead

Thanks, that was just what I was after


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## gwapenut

Is Puly Baby suitable for descaling a cherub? The water went a bit blue last time I used it!


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## Mr Guy Ho

I've just gotten hold of a Heavenly, that is very similar to the Cherub, from what I understand, and it needed a deep clean prior to use. There was tons of scale on all of the water outlets, and the tank was pretty stinky, full of debris. Plus the group gasket was knackered, so my first shot was a disaster, and it had to be replaced.

I backflushed the machine using Puly stuff, but I think the blue is caused by the citric that I ran through the machine, using the instructions paraphrased by thenag, up there. The water from the boiler tastes a bit like lemon, and there's still a trace of it 10 days after I've flushed it through with loads of water. Still, I got impatient, and wanted to start using the machine, so that's my fault. The espresso is great though.


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## Dylan

Mr Guy Ho said:


> I've just gotten hold of a Heavenly, that is very similar to the Cherub, from what I understand, and it needed a deep clean prior to use. There was tons of scale on all of the water outlets, and the tank was pretty stinky, full of debris. Plus the group gasket was knackered, so my first shot was a disaster, and it had to be replaced.
> 
> I backflushed the machine using Puly stuff, but I think the blue is caused by the citric that I ran through the machine, using the instructions paraphrased by thenag, up there. The water from the boiler tastes a bit like lemon, and there's still a trace of it 10 days after I've flushed it through with loads of water. Still, I got impatient, and wanted to start using the machine, so that's my fault. The espresso is great though.


That doesn't sound good, I would hazard a guess there is still a lot of scale within the machine. These descaling routines are good for slight build up, descaled regularly, but badly scaled boilers take days of soaking to completely remove all the scale.

In reply to the OP-

The instructions given sound good, I would think about adding in a step in which you tilt the machine on one side and leave it for 15mins, then the other. Some scale usually develops just above the waterline, and this helps remove that.


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## Mr Guy Ho

I've run 50g of citric in a litre of water through the thing once, and I think the day prior to that that I used just a tablespoon in a litre, which is much less. I thought initially that the machine wasn't reaching a decent temperature, but I think I wasn't waiting long enough for it to warm up.

Is there a how-to of doing a deeper de-scale for a suspect boiler?


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## Dylan

Mr Guy Ho said:


> I've run 50g of citric in a litre of water through the thing once, and I think the day prior to that that I used just a tablespoon in a litre, which is much less. I thought initially that the machine wasn't reaching a decent temperature, but I think I wasn't waiting long enough for it to warm up.
> 
> Is there a how-to of doing a deeper de-scale for a suspect boiler?


A deeper descale basically means stripping the machine down so you can soak the parts and see inside the boiler so you know when your done. There are a few 'restoration' threads on here which show this process.

On an e61 machine you can remove the 'mushroom' to get an idea of what the scale might be like. The group on your machine is not traditional e61, but it looks similar. If you look at the PDF here  on page 8 you see two bolts on top of the group, the larger one is likely the equivalent of the e61 mushroom, if you can get to it and take it out it would give you a glimpse of the internals of the group, and an idea of what the scale build up is like.

'e61 group' refers to an early (and still used in most machines) group head designed using thermal mass for temperature stability.


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## Mr Guy Ho

Blimey, that sounds like more than a couple of hours' work. I'm looking at page 8 of the PDF now; which part number are we talking about here?

And thanks!


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## Dylan

Have a look at page 10, that's the group head.

You will also want to look at removing the shower screen and gasket (fc104, 103) to clean this part of the group, you will probably want to replace the gasket. Coffee oils build up here.


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## Mr Guy Ho

I soaked/scrubbed the screen and plate, so those should be fine. As much hassle as it was to get the tank out and clean the other parts, I think I knew that would be the easy bit. It was a mission to get the old knackered gasket out, but I had a spare for my old Classic, which fits fine. I've since bought a couple of silicone ones from Coffee Hit in the hope that they're less hassle to extract and replace.

Looks pretty straightforward to get those bolts off of the top of the group head, will give that a shot.


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## Dylan

It may give you an indication, but on the other hand a traditional group has a fairly big shaft of metal below that bolt which scale builds up on giving an indication of the insides. As the Fracino one is different it may not collect scale in the same way and therefore not really show you much. It is worth a look however if its easy enough to get at.


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## Mr Guy Ho

I think it'll be pretty straightforward. I took the outer case off really easily the other week, and it's just a couple of bolts on top of the panel above the group head.

Now that I've completely derailed this thread I might as well post any pictures I can get once I've gotten that big bolt off of the top.


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## Mr Guy Ho

Removing the bolt couldn't be done without taking the front controls off, and I was feeling lazy, so I decided to throw citric acid in again.






I've drawn probably a litre or two of water through the machine now, but check out the blue goodness that's still coming out!


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## parsecundo

After using my machine for a number of years in a part of England with little temporary hardness but some permanent harness (calcium sulphate) I though it advisable to descale. This is what I did:-

Switch on and bring the machine up to working temperature, empty the tank by either tipping( very heavy), siphoning or pumping through until the tank is empty. The latter is best.

When the low water level alarm sounds switch off and put the descaling solution into the tank. The descaling solution is 1 sachet of Dezcal dissolved in 1 litre of water.

Switch back on to pump the descaling solution into the boiler. Leave the solution in the boiler for 30 minutes.

Next,add clean water to the tank and continue to pump through in order to purge all the acidic solution from the machine. Keep adding clean water to the tank and pumping through until the pH of the water returns to neutrality or the pH of your filtered water. I used a Ph meter but a few drops of Univeral Indicator could also monitor the pH.

Be aware that several fills of the tank perhaps 4 or more may be needed to entirely flush out all of the acidic solution and return the water to neutrality

Before descaling it may be advisable to do a cleaning run with Cafiza to purge any grounds from the machine.


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## seeq

@thenag credit for that goes to @origmarm


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## thenag

seeq said:


> @thenag credit for that goes to @origmarm


Yes it was. Thanks!


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## gwapenut

Remember you can also empty the water tank by simply pulling it out vertically. It has a valve on the bottom which keeps the water in. Handy for getting rid of every last drop of descaler from the very bottom of the tank.

Not sure if this has an impact on water level sensor reliability anyway though, because my water sensor virtually never goes off in time.


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## parsecundo

What I am not sure about is how much calcium sulphate scale is left in the boiler since this is not removed by any of the normal descaling solutions. A factory descale might get rid of it but my understanding of the chemistry of scale is that a period of use of distilled water will gradually remove it since Ca So4 will dissolve in D H2O. Has any one tried this? I intend to have a go and have ordered digital water hardness device to monitor the process.


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## gwapenut

I'm about to do my annual descaling of the cherub, have run out of my old gaggia-induced stock of puly baby and am looking at moving towards citric acid.

Is this a decent choice?

https://www.amazon.co.uk/Citric-Quality-ecological-descaler-NortemBio/dp/B019Y3KHW4/ref=sr_1_1?s=kitchen&ie=UTF8&qid=1482767659&sr=1-1&keywords=citric+acid+food+grade


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## Mr Guy Ho

I've been using formic acid from Espresso Underground, but I also have this stuff too:

https://www.amazon.co.uk/gp/aw/d/B0057WGZVE/ref=yo_ii_img?ie=UTF8&psc=1


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## destiny

Sorry to revive this, but does anyone know of similar parts/assembly book for Cherub as it was given for Heavenly?


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## MSM

@destiny after a bit of googling I found this....

http://www.fracino.com/downloads/parts/Cherub%20Parts%20Book%202008.pdf


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## destiny

Thanks MSM, I think I must have located it on Fracino website a few minutes before your post


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