Reduced pressure w/ each backflush?

[LeoZ]

im assuming this is normal, but can only assume it happens because the entire system isnt heating up properly, or long enough, after each backflush.

when i do my first backflush after a pf wiggle, the water RUSHES out of the drain. i love that sound, the sound of cleanliness occuring.
after the first one though, lets say 10-20 seconds later, ill do a 2nd backflush, and the water just sort of drips out. no niagara falls.

is this typical? ive descaled, and with detergent backflushes i typically get more rushing than just water, but dont like to detergent backflush often (1-2x month) as everything has been staying clean with daily maintenance. ive also recently descaled, and i assume it went well, since the machine seems to run more 'quietly', well, not quiet, just, more smooth? lol..

ive tried up to 30 seconds wait time, and most of the time, it doesnt make a difference.

what i think it is, but am probably wrong, is that after the first backflush, there is already water in the blind basket, so new pressure buildup is going to be minimal. maybe i should just take off and dump the basket of water each time..

[jesawdy]

what i think it is, but am probably wrong, is that after the first backflush, there is already water in the blind basket, so new pressure buildup is going to be minimal. maybe i should just take off and dump the basket of water each time..

The "woosh" appears to occurr when there is some air under pressure during the backflush. On Silvia, I have the same experience when backflushing.... I can hear it, I don't see it as I always have the drip tray cover on. The first flush is noisy and bubbly, the rest very quiet. If I remove the PF and dump water from the blind basket the woosh reappears. The "woosh" feels good, but probably not any better at cleaning!

-Jeff

[HB]

Leo poses an imponderable in the same vein as When filling lever machine cylinder, where does the air go? OK, I'll go along with it...

I've noticed the extra "woosh" on the first backflush. Other than a momentary "hey, what do you know - louder woosh", I attributed it to trapped steam without further thought. But Jeff's explanation makes more sense: During a regular extraction, the air evacuates through the puck. During a backflush, the air has nowhere to go the first time, so it gets compressed to 9 bar along with the water. When the three-way valve opens, the compressed air expands with far more vigor than compressed water. Ergo, more forceful woosh action. The second time around there's very little air, so less forceful woosh action.

As for the lever machine's trapped air... the question has not been satisfactorily answered.

[LeoZ]

glad to know my wrong guess was right

ill stick to dumping water after each water-only backflush. i enjoy my powerful wooshes!