Abstract: A heat exchanger for a water heater having a burner includes a tube extending longitudinally along a centerline from a first end adjacent the burner to a second end. The tube defines a passage. Strips extend within the passage and are arranged about the centerline. Each strip includes a base and fins extending from opposite sides of the base such that flue gases from the burner flow from the first end to the second end of the outer tube and in channels between the fins.

Abstract: A flue collector box for a furnace having a cooling coil, a heat exchanger, and an inducer blower includes a housing having an interior chamber in fluid communication with the heat exchanger such that condensation generated in the heat exchanger flows to the interior chamber of the housing. A valve is connected to the housing and includes a pair of lips defining a fluid passage through the valve in fluid communication with the interior chamber. The lips have an open condition allowing condensation to exit the valve when the inducer blower is deactivated. The lips have a closed condition forcefully engaging one another when the inducer blower is activated to prevent condensation from exiting the valve.