System and method for trapping and neutralizing condensate in a condensing gas appliance

A condensing fuel-fired appliance configured to generate flue gas, the condensing fuel-fired appliance including a drain system configured to collect condensate from the flue gas, the drain system comprising:

• a drain body defining an inlet positioned to receive condensate in the drain body, a drain opening positioned to deliver condensate from the drain body, a passage extending between the inlet and the drain opening, and a seat surface disposed within the passage;
• a float positioned for movement within the passage of the drain body at a location between the inlet of the drain body and the seat surface of the drain body, the float being configured to move to a position contacting the seat surface defined by the drain body in order to substantially block the flow of flue gas through the passage of the drain body when there is little or no condensate in the passage of the drain body;
• and
• a neutralizing agent positioned along the passage of the drain body for contact with condensate in the passage.