Basically, the answer is: "it doesn't work that way".
Your cost basis when you sell the asset (furnace) is $10, 900. Then you enter the depreciation previously claimed ($545), which is treated as a section 1250 capital gain ("depreciation recapture"). So, yes you effectively write off $10,355 (10,900 - 545). But you deduct it as cost basis, not depreciation.
