Water heater having flue damper with airflow apparatus

A water heater comprising:

• a water tank adapted to contain water;
• a combustion chamber beneath the water tank;
• a burner within the combustion chamber and operable to create products of combustion;
• a flue extending substantially vertically through the water tank and communicating with the combustion chamber to exhaust the products of combustion from the combustion chamber and to transfer heat to water stored within the water tank;
• and
• an airflow apparatus capable of creating airflow in the absence of any opposition to the airflow, the airflow having a pressure, the airflow apparatus communicating with the flue and operable such that the pressure of the airflow slows the exhaust of the products of combustion through the flue when the burner is operating to increase the time the products of combustion reside in the flue, wherein the airflow apparatus is adjustable to vary the magnitude of the airflow during operation of the burner to control the time the products of combustion reside in the flue.

A water heater comprising:

• a water tank adapted to contain water;
• a combustion chamber beneath the water tank;
• a burner within the combustion chamber and operable to create products of combustion;
• a flue extending substantially vertically through the water tank and communicating with the combustion chamber to conduct the products of combustion from the combustion chamber and to transfer heat to water stored within the water tank;
• and
• an airflow apparatus capable of creating first airflow in the absence of any opposition to the first airflow, the first airflow having a first pressure, the airflow apparatus communicating with the flue and operable such that the first pressure of the first airflow resists standby convection flow of flue gases out of the flue when the burner is not operating, and wherein the airflow apparatus is also capable of creating a second airflow in the absence of any opposition to the second airflow, the second airflow having a second pressure, the airflow apparatus operable such that the second pressure of the second airflow assists the flow of flue gases out of the flue when the burner is operating.

A water heater comprising:

• a water tank adapted to contain water;
• a combustion chamber beneath the water tank;
• a burner within the combustion chamber and operable to create products of combustion;
• a flue extending substantially vertically through the water tank and communicating with the combustion chamber to conduct the products of combustion from the combustion chamber and to transfer heat to water stored within the water tank;
• a catalytic converter communicating with the flue;
• an airflow apparatus capable of creating airflow in the absence of any opposition to the airflow, the airflow having a pressure, the airflow apparatus communicating with the flue, the airflow apparatus operable such that the pressure of the airflow resists standby convection flow of flue gases out of the flue when the burner is not operating;
• and
• an additional airflow apparatus creating airflow in the absence of any opposition to the air flow, the additional airflow apparatus communicating with a source of air and the flue and positioned between the catalytic converter and the combustion chamber, wherein the additional airflow apparatus is operable to add air from the source of air to the products of combustion within the flue when the burner is operating to increase the effectiveness of the catalytic converter.