Abstract: A condensate drain includes a body defining an interior space. An inlet opening is in fluid communication with the interior space of the body for allowing condensate to enter into the interior space, and an outlet opening is in fluid communication with the interior space of the body for allowing condensate to exit the interior space. A float is disposed in the interior space for movement within the interior space relative to the body generally along a float axis between a closed position in which the float blocks fluid communication from the inlet opening to the outlet opening and an open position in which the float permits fluid communication from the inlet opening to the outlet opening. The float is buoyant so that the float is moved to the open position by condensate as condensate fills the interior space of the body. The interior space and the float are sized and shaped so that the float is constrained to substantial alignment with the float axis.