How to Replace a Boat's Water Tank Vent

A cracked or broken vent on a boat's water tank offers environmental water -- the water you boat in -- access to your boat's water supply. The water tank vent is connected to the water tank by a 1/2-inch reinforced hose, using a push-on hose barb. The vent is 1/2 inch in diameter, with a curved end, like the P-trap under a kitchen sink. The curved end prevents the ingress of water and contaminants while allowing air to equalize pressure in the tank.

Things You'll Need

  • Jigsaw
  • Vent pipe
  • Adhesive marine caulk
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Instructions

    • 1

      Go below deck to the water tank. Pull the polyester-braid-reinforced, clear PVC vent hose from the hose barb at the base of the water tank vent.

    • 2

      Return to the vent on the deck. Insert the blade of a jigsaw into the water tank vent. Cut through the side of the water tank vent, to the caulking around the vent pipe.

    • 3

      Cut around the vent pipe with the jigsaw. Lift the broken vent pipe from the hole. Insert the new vent pipe through the hole in the deck.

    • 4

      Push the the clear PVC vent hose onto the vent pipe's hose barb. Center the vent pipe in the hole and caulk around it with adhesive marine caulk.

    • 5

      Allow the caulk to cure for 24 hours before using the boat.