I bought a used Isle Royale to put in my cabin in West Virginia. It took me and my neighbor two hours to haul it up the 60 stairsteps to the house but now it is heating great. I could not figure out if I am missing a piece in the fire box, there is a grate that goes into the ash pan. It has nothing covering it so as I burn the ashes fall into the pan, is that how it is supposed to be or should there be a plate over the grate?