Hersteller: Nivona | Typ-/Modell: CafeRomatica NICR 839 | ca. Baujahr: 2017

Hi everyone,

As mentioned in another thread, I have now gotten my hands on a Nivona 839 with a milk frothering problem, just like the 831 I have.
Actually the very first time I tried, it worked. But now not.

Link to video: youtube.com/watch?v=5QIERSUWOck

As far as I can see, no steam is being let out in the bottom by the Drainage Valve.
So I have no spare parts to try out with. Would you recommend (like on the 831) to dissasemble the AuslaufVentil (AV) and extend the spring 1-2mm?

If that doesn't work, I will need to order some new spare parts. Can you help me fill out this list of (cheap) parts that could be useful, bearing in mind that shipping costs are high, and better order some things that are not going to be used, than order twice

• New AV
  
• Some spare hoses for debugging purposes
  
• New drainage valve?
  
• O-rings and silicone
  
• New milk nozzle at the output
  

Anything else?
Please advise if there are other things that could be tested to.
@Moreteen - do you still think it could be a tear somewhere?

Mechanische Kenntnisse vorhanden: JA | Elektrische Kentnisse vorhanden: JA | Messgerät vorhanden: JA

Ok, first problem: I forgot how the AV was assembled in the machine
Can anyone help? There are two arrows, in and out - I guess the IN arrow must be attached to the heater and according to the hoses the most likely placement is with the valve to the left?
Actually it was not mounted with any screws. Is that normal?

Ok, so I think I manage to solve it. Input arrow from heater, output hose to drainage valve and the other hose is the hot water to the ceramic valve.
Is it normal that the AV is connected directly to the heater and not with a hose in between?

Extending the spring in the AV did not solve the problem, unfortunately.

Video of the result here - without cover:
youtu.be/rFfAXY3kKYQ

No inputs from anyone?

Anyone understanding my English, is very welcome to answer in German if it fits them better, I'll just do the translation

I'll try that when I come home. Looks like it could fit. Thanks for the suggestion.

So I tried descaling, and running a milk cleaning program. This didn’t solve the issue.
As suggested I also tried taking the nozzle from my 831 model. Unfortunately it did not fit. Only the plastic spout, so tried switching those, but didn’t yield better results.
I made a video of the steam output and compared it to the working steam output from the 831.

The Nivona 839:


The Nivona 831:


The 839 looks rather uneven in the steam (20ml milk, 80ml frother) so my best guess would be the Auslaufventil.
What do you think?

So you mean the hose that goes into the milk?
I must agree, the two videos looks very much alike.
I can try the hose from the 831, other than that I would need to order a new rubber nozzle. It just doesn’t look damaged at all.

If there was a problem with the rubber steam nozzle, then I would assume that it would never work. But as in the case with the 831, I can actually make it work. This time it worked 4-5 times in a row.
Video of a working milk cycle:
media][/media]

After the 5th time it stopped working and began sputtering again. It seems that if it doesn't get a strong enough flow of milk in the beginning, then it doesn't complete ssuccesfully.

Since there is a physical difference of the two nozzles (839 and 831) I won't be able to fit it. I won't mind ordering different minor parts, if that gets us closer to the core of the problem.

Ahh you mean the black plastic nozzle behind the frame? I would really like to avoid taking my 831 apart again

Yeah, maybe something weird happens when the nozzle gets warm. I will try again a bit later.

I only descaled once - would you recommend multiple times? I'm using Rinza descaler. Could you use ordinary citric acid in a strong concentration, or would you recommend something else?

Amidosulfonic? Never heard of it, but google revealed that it is often used for coffee machines Can you get it in the shop?

Tonight I tried 4 times again - and it succeeded every time.
Tomorrow I will try some more times, stressing it a bit. I don't dare to believe that it has solved itself.

I will report back.

This morning as well, it made a perfect Cappucino. Could it really be the descaling that did it? I dare not to hope, so I will test it further over the next days.

Actually this type of acid, I'm having a hard time finding, other than online. But I will look for it.