Re: Silvia won't pull water for shot. Help!

"Omniryx@xxxxxxxxx" <Omniryx@xxxxxxxxx> wrote:

If AC has been over this and over this already, just ignore me, but...

We have been all over this issue, but it is still worth addressing...

Does anyone have a definitive answer about backflushing Silvia? I note
that Dave (above) says never do it and Rancilio advises against it but
tons of people do it all the time and their machines seem to suffer no
ill effects.

There is not a 'definitive' answer. Rancilio "officially" (whatever
that is) does not recommend it so that they do not have to be liable
for the idiots who will turn on the pump and walk away from the
machine. Virtually every new commercial machine comes with a blank
filter basket or backflush disc so that the machine can be maintained.
Additionally, there has only been ONE (and only one) report of a
machine being damaged in any way by backflushing in the 5.5 years I
have been on this list.

Remember that when backflushing the machine is merely working at it's
pre-determined maximum load which is regulated by the bypass valve in
the boiler. The pressure is reached and the water is pumped back into
the water reservoir through the second hose (the shorter one).

The only difference between backflushing and choking the machine
(grinding so fine that no water gets through the coffee puck) is that
with the puck there is a slight amount of absorption of the initial
pressure flow of the water. With a blind filter the water hammer
effect causes a faster opening of the safety bypass valve and a faster
rise in the water pressure. The difference between these two
situations as far as the machine is concerned is quite minimal.


There are two 'main' dangers to backflushing:

1) It can blow out the boiler gasket which is an O ring trapped
between the brewhead (base of the boiler) ad the boiler's body which
contains the heating element. This O ring is well trapped between
these two halves of the assembly and if it blows out I maintain that
it was faulty and about to fail anyway.

2) The pump can theoretically be damaged if it is left running with
the blank portafilter in place. These pumps are designed as
intermittent duty devices and are not meant to run at full capacity
for twenty or thirty minutes or more as might happen if some
unthinking person was operating it. Even so, they are merely an
electromagnet operating a piston and based on reports here, pumps that
fail in this procedure are damaged by being operated without water. It
is the O rings and other parts of the pump assembly itself that fail.

So what's the story? And if one is not to backflush, how is one to
remove from the 3-way and the lines the gunk that one gets out by
backflushing? Just leave it there? How tasty is that?

The 3-way valve can be disassembled, and the steps are here:
http://member.newsguy.com/~jenkins/silvia/
Backflushing steps on my website at:
http://home.surewest.net/frcn/Coffee/HowToBackflush.html

But cleaning that assembly is just one part of the job. There are
paths in the brewhead that will not get cleansed if the disassembly of
the 3-way is the only cleaning procedure that is done.

Still learning. Always learning.

I recently used Urnex Cafiza to backflush. This was the first time I
used that product (I had used two other brands previously). I highly
recommend Cafiza. It works really well, and you can actually use less
of it, so the additional cost is offset. And it works great!


Randy "ya I do" G.
http://www.EspressoMyEspresso.com


.

Relevant Pages

  • Re: BACKFLUSH Gaggia -- a quote
    ... Hurt the machine. ... Splashing hot water from the drip tray implies potential hurt to oneself, so whilst they acknowledge that backflushing is a generally practiced technique they don't want to see people being hurt whilst performing it. ... I've never backflushed a domestic Gaggia, so I don't know if the splashing they refer to is a high powered splash that can hit the tray with sufficient force to splash upwards into the operators face etc. Backflushing should only be carried out with the appropriate knowledge. ...
    (alt.coffee)
  • Re: Is it safe and wise to backflush my Rancilio Silvia now and then ?
    ... >I'd like to see two pieces of info about blown boiler seals due to ... why is backflushing worse than a totally choked shot? ... The only reason would be what is referred to as "water hammer." ... increase in pressure until the over pressure relief valve opens. ...
    (alt.coffee)
  • Re: Silvia supercharge problem
    ... very careful when backflushing). ... violent steam comes out for about 25 seconds before ... condensing to a solid stream of hot water. ... machine, so to speak, to get it to deliver espresso in a controlled ...
    (alt.coffee)
  • Re: Is it safe and wise to backflush my Rancilio Silvia now and then ?
    ... pressure relief valve mounted to the boiler. ... the valve opens and allows the excess water to return to the ... Backflushing with plain water does little good. ... Check my website for instructions on cleaning and backflushing ...
    (alt.coffee)
  • Re: Well question
    ... On an open loop system it is possible to take water from one well, ... I have an open loop ground source heat pump which operates as you ... You can put the water back - that makes it an injection well. ... Flow rates should be approximately 1.5 to 2 gpm per ton of unit capacity ...
    (alt.home.repair)