I've gotten into the habit of chemically backflushing every other week or so and of course remove the shower screen/gasket on a regular basis as well.

While backflushing I'm curious if there is any benefit of stopping after a few flushes in the mid-position (pump not running, but water not expelled out of group) in order to saturate the shower screen with solution.

Obviously I don't let it sit too long (maybe 5 minutes or so). Is there any benefit to this or is it all in my head?

I do this regularly on old machines. Letting the group soak in puly caff for 5 minutes really makes a difference in my opinion. Some times I get a "double espresso" coming out of the valve after such an operation.

On my own machine that gets regular cleaning this procedure doesn't seem to make such big difference. But then again there isn't much coffee gunk inside my group.

TimEggers wrote:Is there any benefit to [stopping after a few flushes in the mid-position] or is it all in my head?

The cleaning agent will certainly do a better job if you give it a little time to soak. I hadn't considered the lever's middle position in a cleaning context, but I think you're right that it may help because the chamber will be full and the upper valve open. As the heat exchanger recovers, it should pressurize enough to push out dribbles of the water/cleaner solution, slowly bathing the passageway from the brew chamber to the back of the dispersion screen. An interesting tip, albeit a little OCD.



PS: For those following this thread wanting a bit more background information, refer to Is there a purpose for the E61 middle brew lever position? It includes the diagram below:


Lever at the middle brew position

This is the short explanation: Lever up = upper valve open, middle and bottom valve closed, pump on. Middle position = upper valve open, middle and bottom valve closed, pump off. Lever down = pump off, upper valve closed, middle and bottom valve open.

Note: As Ian pointed out in the other thread, the detent position is a slightly different for the Vibiemme and Quickmill. For the Vibiemme E61, the two lower valves are closed and the upper valve is barely open when the E61 lever is raised just above the mid position.

I have been doing that for years. I will run 4 or 5 flushes then pressurize the group, drop the lever to mid position and let it sit for a few moments. Then dump the pressure and run another 3 or 4 flushes before I remove the portafilter, clean out the basket, and do a water flush to flush it out.

O.C.D. are my middle initials
Started this after I removed a screen after a single, no pause backflush. It was not a pretty sight.
Every week :

- Dump water from drip tray. Place baskets in drip tray.
- Add 2ml cleaner to blank basket.

-> Loosely lock PF and start pump. When water runs over PF, do a wiggle or two, lock PF and let pressure build. Drop lever to mid position and wait 30 secs. Lower lever. Loosen PF slightly and repeat 4x.

- Remove PF & rinse. Run a few ml from the group.

- Repeat from -> above.

- Remove screen & gasket and rinse. Wipe out group with wet towel.

The screen and basket always pop out easy-peasy and the back of the screen is pristine.

[ Now dump the drip tray in a large glass measuring cup and soak the PF to clean the spout. ]

Being new to the E61, i don't quite understand this. On my Vetrano, the pump seems to come on very early when lifting the lever. After fully lifting it and running the pump, there is no position when lowering the lever where the pump stops but the pressure is not let out. The only "middle position" I can find has the pump on, but no water coming out.

Is something amiss?

With the power off, can you feel a middle position when you lift the lever?

sweaner wrote:Being new to the E61, i don't quite understand this. On my Vetrano, the pump seems to come on very early when lifting the lever. The only "middle position" I can find has the pump on, but no water coming out.

The pump ON switch is pressed by the cam on the lever; yours apparently sticks out further than most, activating the pump before the lower valves are pushed open. You could adjust how far the pump activation switch sticks out so it engages later in the lever's arc (IIRC, it has two nuts that sandwich the front face), but honestly, it's not something to worry about.

FYI...Both of the Anita's that I've owned/used have the microswitch adjusted so the pump is engaged in the middle position. AFAIK, it's normal for Quickmill machines.

Mike

HB wrote:The pump ON switch is pressed by the cam on the lever; yours apparently sticks out further than most, activating the pump before the lower valves are pushed open. You could adjust how far the pump activation switch sticks out so it engages later in the lever's arc (IIRC, it has two nuts that sandwich the front face), but honestly, it's not something to worry about.

Dan, I suspect that is the issue. There is a middle position but the pump is already triggered. If I want to do this type of backflush, I suppose I could simply shut off the machine and wait a few minutes.