I have been using Kleen-Caf monthly and cleaning my group head with water after each shot. Will attempting to backflush my Rancilio Silvia damage my machine?

Short answer:
When done properly, it is quite safe and even necessary to backflush Silvia.
[Funny, because I had an Aunt named Silvia...]

Long Answer:
Here is a page showing how a 3-way valve works and why backflushing is necessary:
http://home.surewest.net/frcn/Coffee/3way/intro.html

Here is a how-to backflush, applicable to virtually all single boiler machines with the 3-way in the traditional location (like Silvia) and containing no aluminum (like Silvia):
http://home.surewest.net/frcn/Cof...owToBackflush.html

My blind portafilter and Urnex Cafiza came in the mail today. I put 1/4 tsp. of the cafiza in the portafilter of my warmed up Silvia and took the stainless grate off the machine. I turned on the brew switch for 3 to 5 seconds at a time for a total of 5 times. The liquid that drained through the backwash of this 6 month old machine was white with little or no grounds or oils. The jiggling of the portafilter while keeping the brewswitch on put a lot of brown oils and inspissated grounds from under the group head. It appeared that the loosening of the portafilter during cafiza brew really did get rid of a lot of coffee debris. Thanks to another-Jim for his advice. All in all a fruitful endeavor. If I had to do anything different, I would use a little less cafiza in the portafilter. Carl

Kudos to Randy. Thanks, Carl

And don't ask how I know this, but if you get a sharp taste on the end of your tongue on the first shot, you might want to rinse a tad bit better.

Hi Eric, Good point! I have been doing a water backflush and a portafilter "wiggle" daily after the Cafiza backflush. When I look in my driptray a little Cafiza (white) comes out with each water backflush. Rinsing a little more is a great idea. Thanks.

I found on other forums people that had broken the 3-way valve after backflushing. I think is better only use the cleaning powder ( gaggia e.t.c. )

Hi Vasilis, You may be right. After 6 months of home use (10 shots a day), the backflush did not yield any brownish sediment or debris only the Cafiza in water. The "jiggling" of the blind portafilter in the grouphead did release inspissated grounds that routine brushing failed to clean. Thanks for your post. carl

After backflushing for 3 to 5 seconds, 3 times in a row DAILY; Cafiza will still show in the drip tray day after day. What a pain. Any suggestions? My thoughts 1. less Cafiza. 2. don't backflush at all. 3. backflush with water or something else.