How can I check the temperature of the brew water exiting the group head?
To properly calibrate the temperature of any espresso machine it is important to measure the temperature of the water exiting the group head by means of an external measuring device. The displayed temperature and the measured temperature at the group head can be different. To correct this some La Marzocco espresso machine employ a PID offset to compensate for the temperature loss. Adjusting the offset correctly will ensure the displayed temperature is the same as the measured temperature of the water from the group head. All La Marzocco machines are factory calibrated, depending on the final destination the best time to calibrate the PID offset is when the equipment is installed at its final destination.
Strada, Linea PB and GS3 PID settings are accessible through technical programming menu.
It is important that the brew water temperature of an espresso machine is calibrated correctly. Ideally we want consistent stable brew water temperature throughout the entire espresso extraction. On La Marzocco espresso machines the brew boiler water temperature is measured at the most critical point, this is where the cold water meets with the hot water in the centre of the brew boiler. When detected the microprocessor activates the heating element and begins the heating cycle. The temperature of the brew water exiting the group head is held constant by the insulation blanket, surrounding water and the group cap design. This method is very effective but engineers will tell you some heat loss is still expected.