Part 3: Plumbing & Water Systems

These systems are highly vulnerable to freezing. Every drop of water must be removed or replaced with antifreeze.

3.1. Freshwater System:

• Drain Tanks: Completely drain all freshwater tanks.
• Drain Hot Water Heater: Isolate and drain the hot water heater. Remove any heating elements if necessary.
• Pump Antifreeze: With tanks empty, pump non-toxic (propylene glycol-based) marine antifreeze through every tap, shower, and toilet until clear pink antifreeze comes out. Don't forget transom showers, washdowns, and galley pumps.
• Water Filters: Remove and discard any inline water filters.

3.2. Head (Toilet) & Holding Tank System:

• Flush & Drain: Flush the head until clear. Drain the holding tank completely.
• Antifreeze: Pour antifreeze down the head and flush until pink antifreeze enters and exits the holding tank, and then exits the pump-out line if accessible. This protects the pump, hoses, and macerator.

3.3. Bilge Pumps:

• Pour a small amount of non-toxic antifreeze into the bilge so it passes through the bilge pump(s), protecting their mechanisms.