TS reversal, group fine, espresso delicious

The Thermosiphon pipes of my Londinium I sometimes (when an espresso is made, or a flush done, effectively closing the pipe communication and letting them start over) reverse their roles, one heating the group, the other brining back the somewhat colder water towards the heat exchanger inside the boiler. I find it interesting that it's able to do that and be just as effective.

On second thought, it's not really a miracle. If you place a kid on a swing and give it a push, it doesn't really matter which way you call "forward" or "backward."  And every time you take the kid off the swing and ask it to climb back on for the next push, it doesn't matter if it faces you or not.

The espresso was great anyway.

I also took some measurements using a so called 'SCACE device', basically a standardized plastic 'puck' replacing the coffee grinds and a restrictor for the hot water to flow out more or less at the speed and dose of a 'real' espresso. It's used to measure the presumed brew temperature.

Here as well a TS reversal can be observed. See the third shot for this at minute 224. Again the brew group is not deviating from normal temperature equilibrium. The shot on the very left side of the screen is the previous 'real' espresso from the picture above. over the long wait in a 30 C room (summer day, curtains closed, windows closed so no air movement) the group does not even overheat over time.

On minute 204 the cold / room temp Scace is warmed up, slightly cooling the group. A minute after the Scace shots of 214 and 224 I emptied the Scace of remaining water drops and you can see the probe inside the Scace dropping momentarily from being out into the open for a second.