The Hotstart SL Series engine heater is a heavy-duty thermosiphon coolant heater designed for diesel and gas engines that require higher heat output and reliable cold-start performance.
Built for larger engines and more demanding applications, SL heaters deliver increased wattage compared to standard thermosiphon units, with configurations available in 3 kW and 4 kW. This added heating capacity helps maintain optimal coolant temperature, allowing engines to start faster, assume load quickly, and reduce wear on critical components.
Mounted externally from the engine block, the SL Series uses thermosiphon circulation, relying on the natural movement of heated coolant to circulate through the engine. This eliminates the need for an additional pump and allows for flexible installation across a wide range of engine types without requiring a specific in-block fitment.
Hotstart SL heaters are commonly used in:
Standby generators for commercial and industrial facilities
Data centers and critical backup power systems
Hospitals and emergency infrastructure
Municipal and utility equipment
Construction, mining, and heavy-duty equipment
Fleet vehicles and transportation systems
Marine engine applications
Each unit is built with a pressure die-cast aluminum tank for durability and long service life. SL heaters feature NEMA 4 ingress protection, 1-inch NPT inlet and outlet connections, and a high-limit safety thermostat rated to 205?F for safe and consistent operation.
Depending on the model, SL heaters are available with fixed or adjustable temperature control options, or without a built-in thermostat for systems requiring external control.
Compatible with water or 50/50 water-glycol coolant mixtures. Not intended for hazardous locations.
Message us to confirm availability, lead time, and the correct SL heater for your engine application.
