So it tripped even with the supply and return ducts disconnected???
Did he check the gas pressures and check the burners to see the flame???
I fully support the military and the War on Terrorism.
If you don't know, then don't do. If you don't know and still do, then be prepared to pay someone else a lot to undo what you did and then do it right.
If you do know, then do. But do it right. Otherwise, you may not be doing it long.