So there's a lot of people buying Minimas on here at the moment and a few experienced users so I thought a thread dedicated to the Minima with questions / information on the machine would be useful to myself and the others who have recently purchased and are about to take the plunge (and to prevent myself from hijacking other people's threads). One question I have to kick us off is about the brew boiler and PID. For some reason my Minima does not seem to like bring set at 93 degrees. Despite me having it set at 93, the display shows it settling at 94. I'm not sure if this is indicative of an issue or standard behaviour. It occasionally will drop to 93 but then goes up to 94 again

Edit…I've just found the PID Values Explained section at the back of the manual where it explains this is normal.

Mine does the same and I confirmed with other Minima users when I bought the machine.

> @"dutchy101"#p6482 Edit…I’ve just found the PID Values Explained section atvthe back of the manual where it explains this is normal. Very good manual that one…, online version available as well. https://sway.office.com/xofz72xFBgYyiWqi?ref=Link

@"dutchy101"#56 @"HVL87"#57 How have you found the stock filter baskets? I'm already thinking of upgrading, but won't do unecessarily quickly - although that is also partly tamper dependent.

@"PortafilterProcrastinator"#p6679 they are fine. Easier to pull a nice looking bottomless shot - in my opinion that doesn’t mean much. I moved on to a 18g VST to optimise my shots as much as possible.

It's been a bit of a transition for me this week as I've changed from Sage 54mm baskets and didn't have a 58mm tamper until a few days after the machine arrived. I got a new distributor yesterday which has also helped so still finding my feet a bit with the stock baskets, but pretty happy with them so far

Thanks both, if they're a similar ID then I can get a tamper (thinking bravo ATM) first and upgrade the basket later when looking for refinement, rather than just trying to make something palatable!

Yeah - I've got a Nomcore 58.5mm tamper on order and coming this week so will get a better handle on things once that has arrived

@"dutchy101"#p6686 I'd be really interested and grateful to hear how you get on. How are you finding the Minima overall?

Absolutely loving it - so glad I went with it I'm really enjoying using it. How about you? Made my wife a tea using water from the service boiler to drain some water this morning and she commented how much better it looked and tasted (using the zero and remineralised water I've been making up).

The General ACS Minima Thread

simonc

Ah yes I see it just sticking out. Ok I’ll try removing that and have a look inside, and move the ground wire whilst I’m at it

I seem to remember it bubbling at 130c not 100c but not 100%. I’ll keep an eye.

DavecUK

simonc The the surface rust from the limit stat area, where the plate is not stainless (heat transmission), that shows the vacuum breaker has been leaking continually for a while.

simonc

Cheers. Where do I get a replacement? ACS?

DavecUK

simonc They are standard components you can buy in any espresso parts store, but read my post again about repairing it with a cheap 10-pence o ring.

simonc

DavecUK cheers. Just looked, it’s jan 2019. Number B0029.

simonc

So with a sudden realisation in the middle of the night, I realised what’s happened. My citric acid and Epsom salts are in similar containers, and yes, I used 100g of Epsom salts to descale.
Oops

At least I realised after 12 hours and not 12 weeks. Citric acid is already in the boiler and hopefully doing is thing as it should.
I had run several batches of water through the boiler before tasting so was ok expecting no citric acid taste but the water still tasted funny. Now I know why, was very hard.

dutchy101

Ooops - hahahaha

simonc

@DavecUK I don’t see an O ring on here. Is this a fancy memory metal one?

MediumRoastSteam

simonc turn it around and look inside :-)

http://coffeetime.wikidot.com/vacuum-breaker

Now that you took it off, how is it looking inside? Is there a lot of scale build up? Did you manage to syphon the water out?

simonc

MediumRoastSteam

Thanks. It’s like the updated one on your link. Oring looks good and no scale deposits. Very small signs of corrosion on the metal thread. I’ll put new pfte tape on and refit and keep an eye on it.

Edit: standing well back and using a long tool, not your finger, it’s fun / interesting to press down the top of the vacuum breaker and see the steam come out, to prove its working and then re-sealing well.

simonc

Also this is inside the steam boiler. All looks ok with minimal if any evidence of scale after an actual descale with citric acid, only 2 hours. At the top it looks a bit strange as only appears to be damp still ¾ of the way up, and has possibly evidence of some scale on the walls, just a thin layer at the top? I guess that is where there needs to be room for steam above the water, and it’s been deposited from the steam? I got about 1.3l of water out when I drained it.
Happy it looks ok and will rinse and then stay with just bicarb in the water from now on.

Annoyingly my little pen usb camera wouldn’t work on the windows laptop so had to take the Minima to my iMac. Interesting to see inside it though!

https://youtu.be/gv8cM9JKJ78

DavecUK

simonc Put a new o ring on!

simonc

DavecUK it looks ok. But for cost sure I’ll measure and get some new ones. Just general precaution?

DavecUK

simonc it looks ok. But for cost sure I’ll measure and get some new ones. Just general precaution?

No, after 2-5 years, the FK</Viton O rings harden up, especially if you use the steam boiler very frequently…so they look fine but have lost that flexibility which enables them to seal well. People who routinely leave steam boilers on all day, usually get 2-3 years max.

I do get away with many years out of mine, but that’s because I rarely use the steam boilers of my machines.

Parts like these are maintenance parts…like changing oil on a car….and why they should always be put on with either flexible semi permanent thread locker or PTFE.

Amberale

DavecUK

Are they the same valve as on the Vostok?

If so Simon could you advise the Oring size?

I suppose it would be too much of a coincidence that they are the same size as the FCD on the Bianca ( I have almost a hundred ) :)

simonc

Amberale ha yes that would be amazing as I have hundreds of those too.
I’m reluctant to take it off before having a replacement as then I’ll be without a machine, or at least steaming capability.

I’’be just put it all back together but will take it out soon to measure.

Not sure if it’sa coincidence but steaming was a joy this morning.

Wish I’d put the camera in before descaling to check how bad it was if at all.

DavecUK

Amberale Are they the same valve as on the Vostok?

No the Vostok and Evo use a much more expensive memory metal vacuum breaker (LM now use the same one, they sell it for £80 i think). I’d like to see it on the Minima, but I don’t know if it’s affordable. The more expensive breaker has a longer service life..BUT, cannot be fixed using a 10p O’ring!

MediumRoastSteam

simonc - you could measure the inner diameter of the o-ring (I.D.) but measuring the outer diameter of the rod going through it. You can measure the O.D. of the o-ring by measuring the outside diameter of the o-ring, in situ.

Looking at the picture, you should have no problems measuring the thickness. It does not need to be exact. The bevelled shape is the important aspect.

Amberale

DavecUK

Thank you Dave.
I really appreciate you answering all the questions on all the forums you appear on no matter how often we/I have obviously forgotten our year 11 chemistry.

simonc

Finally looking to check on the earth wire. I can’t see a thin black wire from the gicar box but is this the earth to the frame under the service boiler?

Which boiler and top or bottom were the earth wires placed?

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