I've read the first 80 pages of this thread... I'll keep reading, but I'd like to ask some questions that I'm not seeing discussed before I get all the way through.
1) Why do people call the GF heater a boiler ? How does the heating system in a GF work ? I don't see an exposed element in the main vessel. Is there a stove top type element below the bottom of the main vessel that heats the bottom "floor" of the main vessel ? Or is it something else ?
1A) The documentation says there is a 1600 watt element as well as a 600 watt element. Which one is used for mashing ? Could you mod it to run both at the same time ? (120V x 20A = 2400 watts, 1600 + 600 = 2200 watts)
1B) Is scorching the mash or the wort ever a problem with the GF ?
2) Where exactly is the check valve that people keep talking about ? What backflow is it preventing ?
3) Why is there a filter on the pump inlet ? One of the beautiful things about a CFC is that it is *almost* immune to hop plugging. So why is there a filter on the inlet on the pump ?
4) What water/grain ratio does one use in GF mashes ? Just like you'd use in a conventional mash tun ? Or something different ?
5) What are the dimensions and size of the main vessel and the mash tun vessel ?
6) What are the water calculations everyone keeps talking about and why are they so important ?
7) Is there a way to whirlpool the boil and create a hop debris cone in the middle ?
8) Is the CFC large enough ? Can it cool the batch before hops added at flame out lose their potency ?
9) Where is the GF measuring temperature ? Same sensor for the boil as for the mash ? Has anyone stuck a thermometer in the mash grain to see how it compares to the controller reading ?
10) If you could improve anything about the GF, what would it be ? Faster heating, larger batch size, bigger mash tun... what else ? People moving to a GF from a good 3 vessel system, what are you missing ? What can't you do with a GF that you were doing with your 3V ?
Thanks !
Edit: just got the answer to question #2 on page 88, post # 872:
The only downside is safety. If you have the pump running, flow valve open, and you unscrew the arm/chiller, you'll shoot boiling wort into the sky/your face. If you unscrew with the check valve in, the ball inside will not allow wort to shoot out.
If you take it out just make sure to close the flow valve and turn off the pump before screwing/unscrewing the arm or chiller.
Edit II: found the answer to #7 on page 93, post #927:
Whirlpooling and letting it sit for 10min or so before beginning chilling/pumping will leave most of the hop and trub materials in a central cone and you won't have as many clog issues.. Removing the safety spring when it comes time to chill also removes further restriction (I've left mine out permanently)
No issues even with massive hop loads.
Edit III: found some discussion to answer #9 on page 98, in various posts. Tango10 gets it going with this:
Looking to see if people have tested the grain bed temperature once your system is mashing? I did a run today with 9.5 pounds for grain and tested the grain bed temp 4 times to see what its actual temp was. Mine was at least 5 to 6 degrees below the controllers set temp. The controller was reading the correct temp, but actual grain bed was cooler.
In case people aren't aware, this can be an issue with conventional mash tuns as well.