Rancilio Silvia DISCLAIMER: This information is accurate to the best of my knowledge, however, none of it is definitive. If you try any of these suggestions and break your machine, neither myself or any of the other people I quote can be held responsible.

Advanced Cleaning: Backflushing
blind filter
Backflushing the Silvia is NOT recommended by the Rancilio S.p.A. - Any damage you incur from backflushing a Rancilio Silvia is not covered under warranty, so performing this procedure is at your own risk - don't come crying to me if the seals on your pump fail. I repeat, this procedure is at your own risk, and can void your warranty.

Despite the above, this has not stopped many Silvia owners from backflushing.

Randy Glass on explains why you might want to backflush: "Over time bits of coffee debris are carried with the water through the 3-way valve towards and into the drip tray. This happens during a pull when the switch is turned off and the built up pressure is directed through the valve. Not all the coffee makes it into the tray. Some of it sticks in the valve. Eventually you will need to backflush to clean this out."

To backflush, you will need a blind backflush insert, sometimes called a blind basket, and espresso machine cleaner.

Now I quote a Randy Glass post from

"Backflushing is no more dangerous to the machine or yourself than choking the machine with a too fine blend. The machine works far harder when you let it run for ten or fifteen seconds waiting for espresso to drip out then when properly backflushing.

"When backflusing I would caution that:

"1) You do not leave the pump on for more than about one-half second once the pressure builds. Turn it off and let the pressure be displaced through the 3-way valve before repeating. Once the suds from the cleaner are seen in the drip tray stop backflushing and let the cleaner do its work. I just let it sit (with the machine's main switch OFF) and let it soak for ten or fifteen minutes.

"2) Do not backflush a hot machine. Let the machine cool to ambient room temp before backflushing so that the cleaner does not get baked onto hot surfaces making it more difficult to rinse off. Once step one is done, turn the machine off and let it sit with the heating element off and the machine still relatively still cool before proceeding. [See note below from Al Critzer. After this, Randy mentioned that he pre-dissolves his cleaner with hot water and runs the solution bit by bit by adding more to the portafilter each run.]

"3) Use a cleaner designed for such purposes such as "Urnex Espresso Machine Cleaner" and NEVER run this stuff through the pump or boiler!!! It is not a descaler and this WILL damage the machine.

"4) Once the cleaner has done its job, clean out the portafilter, reinsert the blind filter, and turn on the machine again. Continue the backflushing procedure (turn on the brew switch, wait the one second or so for the pressure to build, turn off the brew switch and allow the pressure to be fully relieved through the 3-way valve) until clean water comes out of the 3-way valve.

"5) Once that is accomplished, remove all the parts you can and manually clean with portafilter brush and towel using clean, hot water. Clean as thoroughly as possible.

"6) Once done, reassemble the machine and pull one or two double shots and discard them. They could contain some residual cleaner, and will taste terrible if not be actually hazardous to consume. The machine will need a bit of seasoning as well. [Meaning what I am not sure. I'll have to ask sometime!]

"Backflushing improperly MAY void the warranty, but allowing the 3-way to eventually clog up with coffee debris will necessitate disassembly of the valve for cleaning which would also presumably void the warranty if done improperly. Just don't do it improperly."

Al Critzer (also disagrees with Randy on one major point: "Backflushing should be done with the machine at operating temperature. Purocaff, pulycaff, Urnex, all rely on hot water to emulsify. We all know that coffee has minimal reaction to cold water, and coffee residues are no different. Backwashing with cold or warm water has the additional negative side effect of depositing detergent residues in the group and solenoid valve. You don't want that in your next cup of coffee." [I assume that Al would both backflush and let the cleaner sit with the machine on and hot in steps 1 and 2 above. You have the information now, dear reader, and you can make your own call on this one!]

Randy Glass also notes that even with backflushing, some gunk still builds up in the solenoid valve and will eventually cause it too leak. Dissassembly of the valve will be required for a more thorough cleaning. He implies that six months to a year is about right for valve cleaning. Instructions on this are linked to from my main Silvia page.

NOTE: I backflushed my Silvia every few months, and always heat it up beforehand. It makes a noticable difference in how the espresso tastes - always a great improvement.

Copyright © 2002 by John Holder