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Krups EA8250 Liquid Remains in Brewing Chamber

DanS

March 04, 2021 11:04 pm

Unregistered

Brief history, this machine was stored away where I worked and I decided to clean it and get it back in use. I've rebuilt many espresso and coffee machines before. After a tear down and deep clean the machine seemed to work fine for around 8 months. Then I noticed a leak out of the bottom of the brew chamber and the brewing punch started to push up past the gaskets and leak. Replaced both the piston gaskets and the lower brew group gasket, problem resolved.
Now the machine leaves residual liquid in the brewing chamber after a coffee cycle. So far I can run a rinse and cleaning cycle with no issue or liquid left behind. I can also make an espresso with very minimal noted left behind. When I set it to make a regular coffee the machine runs through the cycle and finishes fine but when the lower brewing punch lifts the coffee puck it is sopping and there is liquid left behind in the chamber that splashes when the punch springs back down. The full volume of coffee/espresso is made and makes it to the cup fine, the brewing chamber does not relieve all the residual liquid before expelling the coffee puck.

I have tried running the cycles with and without coffee beans being ground into the chamber and the splashing behavior is the same. I just finished replacing the relief valve and also removed the brew group and cycled hot cleaner and descaler through the lines using an external pump to ensure all lines are clean and clear. These fixes have made no change. The distributor is free of obstructions and works fine as well as all lines being unobstructed. I can get hot water, steam, run cleaning cycles, etc without any issues.

From the differences in the rinse, espresso, and coffee cycles it is as if the discharge stage of the coffee making is not as long a duration enough to allow the chamber to fully remove excess liquid. I am guessing this started to occur after replacing the seals because the chamber no longer is leaking as it was before and now the residual liquid remain.

Thoughts?

DanS

March 30, 2021 07:06 pm

Unregistered

Update:
After some more work to try and troubleshoot my issues I found that the sensor contacts soldered to the front edge of the boiler needed to be reattached. Once doing this the issue of liquid remaining in the chamber after coffee is made seems to have fixed itself. Not sure if the items are related to each other, but now the machine will at least brew without splashing liquid all over the inside.
Now that that is resolved the machine now won't grind for more than a few seconds resulting in fairly weak coffee and pucks around 1cm think. I have tried to use the hidden startup menu and have cycled between 1-5 to no change. I sometimes wonder if using that menu at all actually does anything as there is no way to confirm the setting, you simply have to unplug the unit and plug it back in to resume operation. Given that aspect I doubt it even saves the 1-5 setting.
Given all this, are there any other ways to increase the time the grinder runs in order to increase the amount of ground coffee that goes into the chamber?

DanS

April 14, 2021 07:11 pm

Unregistered

Update 2:

After some more tinkering I think I was able to get the grind adjustment setting to save.
After removing the various accessories from the unplugged machine and holding the PROG button for a few seconds and then plugging the machine in (as has been described in other posts in the forum) I was at the menu that supposedly allows for grind adjustments 1-5. I made a selection of 4 and then started replacing the accessories on the machine. Once everything was back in the machine display changed to a sentence in French at which point I just started pressing and holding some of the buttons to try and get it to move on since no individual button press would trigger a change. I think I was holding down the steam or hot water button when the machine initiated a restart. The system restart was in French so I had to go back into the menus to change to my preferred language. Once that was done the machine has been working without issues.
Hope this helps someone else out there.

DanS

June 03, 2021 11:28 pm

Unregistered

After several weeks of making coffee without any issues it has begun to revert to it's old problems. Nothing has changed with the machine other than time passing and some coffees being made. It is once again grinding way too much coffee ( 9 second grind time vs 7 second I previously had set by using the PROG menu) into the chamber and the previous method I mentioned to change that is not making any difference. It is also leaving liquid in the brewing chamber again and when the piston ejects the old coffee it springs back into place splashing everything out and making a mess inside the machine.
The NTC has been replaced and I've confirmed it's readings with a multimeter. I can get hot water consistently at about 85C which is what I've understood to be normal. The drain in the bottom of the brewing chamber and the associated tube and valve are not obstructed.
I suspect that either the machine is not leaving enough time after brewing to drain all the liquid or (since it is a pressure driven process) it isn't building enough pressure to force out the remaining liquid in the time allowed. Either way I am stumped and at a loss for options.
The strange thing is that I can run a rinse cycle and it works perfectly with no remaining liquid in the chamber. As soon as I try for any coffee, even without any coffee being ground into the brewing chamber, it leaves liquid behind and splashes.
Does anybody have any ideas or suggestions before I give up and throw this machine in the trash with all its shiny new parts?