What is that advantage and disadvantage of boiler water temperature? It is not simple to get that temperature and that temperature has some variation with height in the boiler. In fact, boiler temperature stratification is the reason the Gaggia works. Hot at top and the cool water enters the bottom, thus the central stand pipe.
Just as an aside, I don't think anyone expects a PID to have any impact on the intra-shot temperature of a Gaggia. The PID is only expected to give a repeatable temperature at which to start the shot.
Actually, I think all my questions are answered here. Summary: it does seem possible to achieve pretty flat brew temps by adding the right amount of boiler heat during the shot. I don't yet understand all the terminology, but it seems that this is possible to accomplish with PID alarms. I think I'll try the same thing manually with a second dimmer switch set to ~40% power, wired to the boiler, that I turn on once the shot starts. ;DAfter a few more such mods, my machine will be called the Gaggia/Rube Goldberg Classic, and I'll be the only one who can figure out how to use it. 8)
Is your dimmer rated for Gaggia heater wattage? You may be the only one dare use it
The Gaggia elements being in the boiler wall induce a time lag for turn on of energy to heat the boiler and that heat to get into the water. Additional time lag comes from the sensor being in the wall, not in the water. Sensor in the water may have some advantage of less lag, but the process will still have some lag. An element in the water might heat faster, but the Gaggia is fairly rapid with the high wattage and small boiler, almost a thermoblock. I can see a possible downside to sensor in the water for the average user. The sensor separated from the element seems like it could lead to the possibility of overheating and melt down if the boiler was very low on water. Perhaps why not adopted by Gaggia even though they used it on KA Proline. I suspect that the sensor in the boiler works very well and should also control intrashot drop.Pizzaman, Curtis, I have followed some of your work and posts at HB since you posted in CG on the PID thread. I had not seen your specific sensor in the boiler well. How are you controlling idle, vs heat during the brew? Do you preheat the incoming water?
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