A device (100) and method is provided for automatically removing water or accumulated moisture from a breathing circuit. The device includes a housing (101) with breathing circuit flow entry and exit ports (130,132) and a water drainage port (120). A buoyant body (112) in the housing can mate with a float valve seat (121) to seal the drainage port, and is moveable to open the drainage port when sufficient liquid (L) accumulates in the interior space. The buoyant body displaces a substantial portion of the housing inner compressible volume. Water is automatically removed by a water vapor permeable container (102) coupled to the housing receiving flow from the drainage port, or the device is coupled to a source of suction, further including at least one bleed port (360) fluidly coupling the source of suction to the surroundings, acting with a valve element (388) to equalize any pressure differential between the housing interior space and suction connection, when no water is accumulated in the device.
