The Thermostart H2 Self-Circulation Engine Heater Without Pump is an electric coolant heater or circulation heater for various water-cooled engines. When the coolant heating, it will be pushed to the top of the engine by a Thermosiphon. Therefore, no matter what ambient temperature,the engine can easily achieve full power start and effectively avoid cold start mechanical damage. It can be widely using for the Diesel gensets, Gas gensets or Large equipment with diesel engine.