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 is heating, it will be pushed to the top of the engine by a thermosiphon. Therefore, no matter what the ambient temperature, the engine can easily achieve a full-power start and effectively avoid cold start mechanical damage. It can be widely used for diesel gensets, gas gensets, or large equipment with diesel engines.