HWP30N is smart forced circulation water heater of engine. When engine operation temperature is below 4ºC, engine liquid coolant/lubricating oil may be coagulated to solid state in starting phase and lose lubrication or cooling effects, so that it may damage the engine. Therefore, heater shall be installed for engine to ensure normal starting and running. 
It has lamp indication function, which can indicate all kinds of heater statuses. Heating temperature can be set by users, and dry burning prevention and overheating protection are fitted.