Water heater having multiple heating coils arranged in parallel flow paths

Claim 1

A HOT WATER HEATER COMPRISING A CASING, A GAS BURNER LOCATED IN THE LOWER PORTION OF SAID CASING, A FIRST WATER MANIFOLD SITUATED AT THE UPPER PORTION OF SAID CASING, A SECOND WATR MANIFOLD SITUATED AT THE LOWER PORTION OF SAID CASING, EACH MANIFOLD COMMUNI CATING WITH A WATER FLOW CONDUIT, A PLURALITY OF HOT AIR DUCTS DISPOSED WITHIN SAID CASING, A HEATING COIL DISPOSED IN EACH DUCT, ONE END OF EACH COIL COMMUNICATING WITH ONE MANIFOLD AND THE OTHER END OF EACH COIL COMMUNICATING WITH THE OTHER MANIFOLD TO PROVIDE PARALLEL CIRCUITS BETWEEN SAID MANIFOLDS, A FIRST WALL DISPOSED TRANSVERSELY WITHIN SAID CASING, AND A SECOND WALL FORMED TRANSVERSELY WITHIN SAID CASING IN SPACED RELATIONSHIP WITH RESPECT TO SAID FIRST WALL, SAID DUCTS EXTENDING THROUGH SAID WALLS AND SECURED THEREIN, THE MARGIN OF SAID WALLS BEING SECURED TO SAID MANIFOLDS, SAID WALLS, SAID DUCTS AND SAID MANIFOLDS THEREBY DEFINING A COMPOSITE SUBASSEMBLY, MEANS FOR REMOVABLY SECURING SAID SUBASSEMBLY WITHIN SAID CASING WHEREBY SAID SUBASSEMBLY CAN BE REMOVED BY WITHDRAWING THE SAME THROUGH ONE END OF SAID CASING, A HEATING MEANS CONTROLLED IN RESPONSE TO THE FLOW OF WATER IN SAID CONDUITS FOR ESTABLISHING HOT AIR FLOW THROUGH SAID DUCTS,