Flue systems for fuel burning devices

A fuel burning water heater comprising:

• a housing comprising:
• a burner disposed within the housing;
• and
• a flue gas outlet disposed on the housing and in fluid communication with the burner;
• and
• a flue gas outlet assembly affixed directly to the housing of the fuel burning water heater, the flue gas outlet assembly comprising:
• an inlet chamber configured to receive flue gas from the flue gas outlet;
• an outlet chamber;
• and
• a door disposed between the inlet chamber and the outlet chamber, the door being configured to selectively permit the flue gas to flow between the inlet chamber and the outlet chamber,
• wherein the door is configured to bias closed and to open upon a flow of flue gas from the inlet chamber to the outlet chamber.

A water heater system comprising:

• a common vent manifold configured to exhaust flue gas;
• and
• a plurality of fuel burning water heaters, each of the plurality of fuel burning water heaters comprising:
• a housing comprising:
• a burner disposed within the housing;
• and
• a flue gas outlet disposed on the housing and in fluid communication with the burner;
• a flue gas outlet assembly affixed directly to the housing of at least one of the fuel burning water heaters, the flue gas outlet assembly comprising:
• an inlet chamber configured to receive flue gas from the flue gas outlet;
• an outlet chamber;
• and
• a door disposed between the inlet chamber and the outlet chamber, the door being configured to selectively permit the flue gas to flow between the inlet chamber and the outlet chamber,
• wherein the door is configured to bias closed and to open upon a flow of flue gas from the inlet chamber to the outlet chamber;
• and
• a flue pipe condensate drain assembly comprising:
• a condensate inlet;
• a condensate outlet;
• and
• a float valve disposed between the condensate inlet and the condensate outlet,
• wherein the float valve is biased closed and is configured to open to permit a flow of condensate from the condensate inlet to the condensate outlet upon a sufficient amount of condensate collecting proximate the float valve.