Fireplace heating system

In a heat exchange system wherein relatively hot gases pass through a flue, a first heat exchanger is disposed in said flue with a heat exchange medium flowing therethrough for absorbing heat from said relatively hot gases, a second heat exchanger is disposed in a relatively cool area, and said second heat exchanger is communicably connected with said first heat exchanger so that said heat exchange medium flows through said second heat exchanger for dissipating heat from said heat exchange medium, the improvement wherein said first heat exchanger comprises a first manifold for receiving said heat exchange medium from said second heat exchanger, a single helical coil having a first lower end fixed in communication with said first manifold for receiving said heat exchange medium from said first manifold, and a second upper end, a second manifold adjacent and parallel to said first manifold, said second upper end of said single helical coil being fixed in communication with said second manifold so that said second manifold receives said heat exchange medium from said single helical coil, and coil support means for maintaining successive convolutions of said single helical coil in spaced relation with respect to one another, said first manifold and said second manifold being so constructed and arranged as to receive a like pair of manifolds in end-to-end relationship therewith, said like pair of manifolds having a second single helical coil therearound and in communication therewith, said single helical coil and said second single helical coil being two of a plurality of single helical coils, all of said plurality of single helical coils being co-axially positioned in said flue, each of said plurality of single helical coils having a first end fixed to said first manifold and a second end fixed to said second manifold so that said plurality of single helical coils are connected in parallel with one another.