on a pump machine thats just by design, soon as pressure releases. so the need to back flush
this is an added feature,
the soupy pucks add to cleaning thats all im saying, this goes for any machine like that.
when i first started with my londinium levers the moving the cup and dry knock out pucks were great, as was the cleaning side, when i moved back to the bianca wet pucks became the norm as did the need for back flush, and greasing, its just an added thing thats all.
for me personally its not a feature id use even if fitted, it probably will become the norm, im hoping im not in the market now for another 10yrs.
this is the kees instructions :
Back flush group Back flushing cleans the group and conduits from coffee residue which influences the taste of the extraction since fresh (hot) water is transported to the coffee bed through these parts. It is advised to back flush the groups at least once a day and more often when the machine is intensively used. Described next is the back flush procedure for an individual group.
Procedure 1. Remove the filter holder, flush the group briefly (with flush-handle).
2. Clean the group screen and group seal with the plastic group brush.
3. Pry the filter basket (e.g. with the group screen extractor) from the filter holder (see Figure 21) and replace it with a blind filter.
4. Scoop 1 teaspoon of coffee dissolving powder in the blind filter and lock the filter holder in the group.
5. Pull the brew-lever into locking position, unlock when pressure no longer rises (appr. 3.5 bar): pressure will quickly rise to appr. 9 bar.
6. Keep away from the reach of the brew-lever, then relief pressure (with handle); the brew-lever will return to resting position very quickly, do not remove the filter holder.
7. Repeat steps 5 and 6 eight times (pressurise, then de-pressurise).
8. Remove the filter holder from the group, clean the blind filter by flushing it under the tap, flush the group for approximately 5 seconds to remove possible powder from the group screen. Now do it again without adding cleaning powder to remove all powder from the group:
9. Lock filter holder in group, pull the brew-lever into locking position, unlock when pressure no longer rises (appr. 3.5 bar): pressure will quickly rise to appr. 9 bar. Keep away from the reach of the brew-lever, then relief pressure (with handle); the brew-lever will return to resting position quickly. Remove filter holder and empty in drip-tray, remount filter-holder.
10. Repeat step 9 four times.
11. Pry the blind filter from the filter holder and replace the filter basket.
Clean program Maximum water-pressure during the clean program will be incoming pressure and thus not as high as when you perform the back-flush manually and may thus not be as effective. The groups will simultaneously pressurise for 15 seconds (with pump active when installed) 8 times in a row with a pause of 9 seconds in between. The LEDs on the flush/relief unit will flash during the cleaning program, the digit displays continue to show the temperature. Procedure
1. Remove the filter holders, flush all groups (with handle).
2. Clean the group screen and group seal with the plastic group brush.
3. Pry the filter baskets (e.g. with the group screen extractor) from the filter holders (see Figure 21) and replace them with blind filters.
4. Scoop 1 teaspoon of coffee dissolving powder in each blind filter and lock the filter holders in the groups.
5. On the touch screen, start the cleaning program (the LEDs on the units start to flash).
6. One-by-one pull the brew-levers into locking position (the LEDs remain flashing). While 7 (and 10) is in progress, clean the filter baskets.
7. After 8 pressurising cycles the LEDs stop flashing, the program has ended. 8. Unlock the levers, relief pressure (with handles).
9. Unlock the portafilters and clean them under running water, replace in groups.
10. Start the cleaning program without cleaning powder again to remove all cleaning powder from the groups.
11. Pull levers into locking position, wait until the LEDs stop flashing (the program has ended). 12. Unlock levers and return to resting position (relief). 13. Replace blind-filters with filter baskets.
sorry for the derail lol
fwiw i like the design of the nurri i think its a great looking machine, i did look at them but decided it was too big for my counter, this was bianca time