Heater Craft engine coolant-powered cabin heater is a bulkhead-mounted, hydronic marine heater for heating the boat's cabin. It utilizes hot coolant from the engine's cooling system, while an electric fan blows the heated air directly into the cabin.
The heater has a nominal heat output of 28,000 BTU/hour, equivalent to approx. 8.21 kW. The output is measured at a water flow of 11 l/min, a coolant temperature of 76 °C, and an ambient temperature of 15 °C. Actual heat output therefore depends on engine temperature, coolant circulation, and the design of the installation. The product's 12 V power supply drives the fan; the heat itself is provided by the engine's coolant.
The fan motor has three speeds with power consumption of 3.9 A, 5.0 A, and 7.7 A, respectively. The included panel switch has four positions for off, as well as low, medium, and high fan speed. The kit includes the heating unit, panel switch, electrical cable, and mounting screws.
The bulkhead-mounted design is intended for direct grille mounting. Installation requires suitable coolant hoses and engine-specific nozzles, adapters, or fittings, which are not included in the kit's contents. Coolant can be routed through the heat exchanger in either direction. The heater must be placed with sufficient air circulation, and hoses must be routed without kinks and kept away from moving parts, sharp edges, and hot surfaces.
The heating unit should be mounted below the level of the cooling system's fill or pressure cap. If positioned higher, venting may be required. If the hose run between the engine and heater exceeds approx. 4.6 m, or the heater is mounted more than approx. 46 cm above the engine level, the installation may require a separate circulation pump. Low engine RPM can also reduce coolant circulation and thus heat output.
The documented wiring for the 3-speed controller uses a yellow wire for low speed, red for medium speed, orange for high speed, and black for negative/ground. The fan motor and switch must be protected with a 15 A fuse in series. Always check terminal markings and the wiring diagram before connecting. The engine must not be run in a closed or poorly ventilated area during testing due to the risk of carbon monoxide from the exhaust.
Key featuresEngine coolant-powered cabin heating
Nominal heat output: 28,000 BTU/hour, approx. 8.21 kW
Tested at 11 l/min, 76 °C coolant, and 15 °C ambient temperature
12 V DC three-speed fan motor
Power consumption: 3.9/5.0/7.7 A
Four-position panel switch included
Direct bulkhead/grille mounting
Electrical cable and mounting screws included
Recommended fuse: 15 A
