Engine Water Filters

Boat engine water filters are essential components for ensuring proper engine operation and longevity, especially in water-cooled inboard and outboard engines. There are different types of filters, each with a specific function:

Main types of water filters for marine engines:

1. Water/fuel separator filter (racor):

   • It does not filter sea water, but any water that may be present in the fuel (diesel or petrol).

   • Essential to avoid engine damage due to fuel contamination.

2. Raw water strainer:

   • Filters seawater before it enters the engine cooling system.

   • Retains algae, sand, shells, plastic or debris that could clog the pump or lines.

   • It must be inspected and cleaned regularly.

3. Fresh water filter (in dual circuit systems):

   • Present in engines that use a closed cooling system (fresh water inside and sea water outside).

   • This filter keeps the fresh water circulating inside the engine clean.

When to replace or clean filters:

• Fuel/water separator filter : every 100 hours or once a year.

• Raw water filter : Visually inspect each outlet and clean monthly or if you notice a drop in cooling water pressure.

• Fresh water filter : if equipped, according to engine specifications.

Practical advice:

• Keep a spare filter on board.

• Make sure the seals are always in good condition and well lubricated (seaweed or specific grease).

• Choose clear filters where possible for easier inspection.