A boat heater can help extend your boating season by keeping crew members comfy when there’s a chill in the air. One of the most effective for inboard or sterndrive boats is the Heater Craft hydronic marine heater, which works much like your car heater, using hot cooling water from the engine and a variable-speed fan to feed warm air to vents at various places in the boat.
Before installation, lay out the system to make sure the mounting location of the heating unit and the routing of the hoses will work. You might also need to adapt some of the plumbing fittings depending on how the cooling system on your particular inboard engine is configured. Here’s an example of how we installed the twin-outlet 28,000 Btu Heater Craft 200 Pro kit on a 24-foot cuddy cabin boat.
Skill Level: 3.5/5
Time to Complete: 6 Hours
*Heater Craft 200 Sport Kit with twin heating vents, ducting, brass fittings, heater hose, hose clamps ($499.99; heatercraft.com)
*Brass shut-off valves (2) for plumbing on the engine ($19.99 each; westmarine.com)
*Power drill and bits
*1-inch hole saw (for access holes to run the heater hoses)
*3-inch hole saw (for the louvered vent mounting)
*4-inch hole saw (for Hot Tube vent mounting)
*Extra plastic wire ties for supporting hoses and ducting
*Open- or box-end wrench set
*Teflon plumbers tape
Quick Tip: If you’re tapping into a closed cooling system for the hot-water and return hoses, make sure the heating unit is mounted below the radiator cap. Otherwise, trapped air might block the circulation of water through the heating system.