Heres a walk-up shot on a Silvia (not watching the boiler cycle). Temperature is measured with a K-type thermocouple inserted on top of the coffee puck over the lip of the basket. So the water temp between the shower screen and coffee puck is measured. I did a couple of these measurements in succession and they all came out low. Well below the accepted brewing temperature range.
Subsequent measurements on a different day and different machine and synchronized with the boiler cycle yielded proper brewing temps. My take home message is that you need to temperature surf if you want consistent results with a Silvia.