I'm saying you didn't have enough sap to be boiling on a 2X3. You need to add sap as you go. A little all the while and more when you draw off. I wouldn't fire that up unless I had 100 gallons to make a day of give and take. Being shure till you get a feel for it that you have plenty of sap to flood it if things go bad. A pal of sap at hand is also important. Meter the sap to it so that you can keep it at 2" deep till you can bring it down some and be comfortable at 1 1/2 inches. Once it startes to turn it can turn fast and burn easy. Need to feed it as the steam comes off. It will move throught the cannals by density as the less dense Sap comes in the more dense moves away from it and ends up at the draw off. As for the fire YES, hot and fast burn. heat! heat!! heat!!! All over the fire box side to side top to bottom FIRE!!!! That will get a boil going all over the pan.