Checked Southbend flat top unit, found flu for griddle and 2 burner range blocked in rear. Took back panel off and cleaned out so unit could breath. Also cleaned air vent in regulator. Cleaned out front of grill behind splash guard. Tested unit, calibrated left side of griddle 50 degrees. Chef wants right side hotter. There is a pile of food and carbon under range burners, they will clean. Unit operational, job complete.