deusdeorum wrote:I can't say I solved it, but I found a workaround. Before each cup (after the cooling flush) I turn on the pipe for <3 seconds (before the click sound) 3 or 4 times. I can tell, that the pressure is fine by the sound (it becomes quiet). And by doing this I have necessary consistency every time.

More or less what I am doing. Today I spent a good 3 pounds messing around with everything. With the same grind settings, I got outputs that range from 40 gr to 60 gr.

I had the same problem with my Oscar but I turned the prestostat a little bit to the minus, the temperature droped and it is much better now!
Here is a before and after photo of the prestostat > https://s10.postimg.org/iru19azg9/Image_1_jpg.jpg
If you have a Sirai (some Oscars have), you must give it a full turn.
The waterflow without a filled portafilter (without backpressure) is not always the same but that doesn't matter, under pressure the result is good!

The only time when the pressure on the machine is not reliable is if you brew when the boiler kicks in. Just wait untill the red light goes out.

I've been reading these boards for a while but have never posted. Hi, wave

I just purchased and unpacked a new Oscar II a few days ago and am having the same issue with variable water flow, unrestricted, just using an empty portafilter. The time is always the same (as I did some prior programming with the espresso dose), but the water output is extremely variable -between 2 and 4 oz.

My other thing is what seems to be a heating issue that doesn't seem right. If left on the machine moans and groans and thunks away, and every 5 minutes or so, there is a bigger "thunk" and the re-heat button lights up and there is the sound of water running inside of it. It doesn't seem right that the machine needs to re-heat this often or should be this noisy, just sitting there? Ludicrous actually.

Also, the reheat button has come on a few time in the middle of a running a shot, so then the shot is wasted, because the machine stops.

These issues don't seem to make sense and there's nothing else I have found "out there" that describes similar issues around trouble shooting.

Help? Thanks!

I just unpacked my new Oscar, and it sounds very much like my experience so far.

I can't get it to start earlier than about 20 seconds.

Hey guys,

I have the answer.

I recently got an Oscar 2 as well. It seems it is normal (unfortunately) for the machine to need to pressurize before a real shot.

I do not think there is anything broken I think its just a poor design. This is my solution/workaround that I have come up with that works everytime but I still think its stupid to have to this everyday.

After the machine is heated up and ready to go. Before I pull my first shot, I swap my portafilter basket with an EMPTY PRESSURIZED filter basket and let run the full shot. This does two things. It pressurizes the machine, and flushes it. Now, the machine is ready to go. I only do that prior to my first shot or if the machine has been sitting. After that I load up my double shot basket and make my lattes (no more flushes). Works everytime

I hope this helps, and shame on nuova simonelli for this apparent poor design.

~Adam

Hi all, really interesting forum and thread . A short recap of the solutions I've read here:

• Turn pump on and off before click sound 3 to 4 times before each shot.
• Adjust pressurestat to lower temperature
• Pull empty shot using an empty pressurized filter basket before each shot

For a couple of months my solution was to program the two-coffee-button to a very long period, and use it to manually start and stop the shot based on the amount of coffee delivered in the cup. While I already accepted this as a workable solution (a lot of high end machines are manual), the problem with the varying output seemed to have disappeared when I:

• (1) switched to a different type of coffee bean and
• (2) started to fill the filter basket to the top (scrape of excess cofee using my index filter).

I still need to experiment more, but this seems to confirm the theory that it all has to do with how the pressure is build up in the filter basket / portafilter.

I would love to hear if my solution works for you as well. For the sake of completeness, this is my current routine:

• Before first shot, do a dragon flush, with empty portafilter in place. Two side benefits: heats cup and group.
• Froth milk, let it sit on countertop (helps the milk to become more firm)
• Fill basket to the top, tamp, install portafilter and hit the coffee button
• Pour frothed milk over coffee

Hi Adam

"After the machine is heated up and ready to go. Before I pull my first shot, I swap my portafilter basket with an EMPTY PRESSURIZED filter basket and let run the full shot"

What is an empty pressurised filter basket?

Thanks.

KS

its a portafilter basked that has a pressure regulator on the bottom instead of just holes. you need a 58mm one, I am using one from my old gaggia classic.

here is a google search, they dont seem very expensive.

https://www.google.com/search?hl=en&sou ... OTjXS-UsAw

Google is your friend: http://guide2coffee.com/guide-2-coffee- ... ed-baskets

Thanks, Adam.