4. Winterize other drains.
It’s easy to forget other lines or hoses that may have water or fluid in them. Here are other areas to flush with antifreeze:
Shower sump pump. If you have a shower area drain with sump pump, pour antifreeze into the drain hole and pump it overboard.
Icebox or refrigerator/freezer. Most have drains with a hose that drains to a sink drain line or elsewhere. You may not be able to tell if there is a horizontal section of that drain line under cabinetry or elsewhere where water may have accumulated. Unless you’re sure, pour some antifreeze into this drain also.
The bilges. In most sailboats, water entering the boat at any place eventually ends up the bilges. In most cases you can open a drain plug (or remove the knotmeter impeller to open a drain hole), but even if you think you have the bilge completely dry, water may seep in from other slow-draining areas (or down the mast, if the mast stays up). Water that freezes in the bilge can damage a bilge pump, other equipment, or hoses. Pour some antifreeze into any area in the bilges that can collect water.
Cockpit and deck drains. Wait until just before you put on the boat’s winter cover, then pour antifreeze through these drains also. To be sure you’ve displaced any water in the drain hoses, have someone under the boat with a clear plastic cup to catch the draining water until it changes color.
Watermakers are delicate, specialized equipment that must be conditioned and winterized following the manufacturer’s directions.
Is That Everything?
Take a look around your boat to make sure you haven’t forgotten any other water lines. If you have a galley saltwater hand or foot pump, remove its inlet hose and pump water through it (the same as with the head’s inlet hose). If you have a deck wash-down pump, do the same. Remember: any water that has entered the boat at any site during the season must be displaced by antifreeze before it freezes in the winter. Don’t assume that water will have completely drained out of any line or hose simply by gravity: there are always places, such as inside pumps, where water may remain.
Then make a list of every step you took, every water line and fixture you drained, so that next year it’s easier and you don’t forget that one little thing that will ruin your spring launch!
In the spring, pump out remaining antifreeze, refill the water tanks, and thoroughly flush all the systems.
While winterizing, this is an excellent time also to change your oil, an easy process with the right equipment.
