Thermostat and cooling system having the same

A cooling system comprising:

• a coolant pump supplying a coolant to an engine;
• an integrated thermal management valve receiving the coolant from the engine and distributing the coolant, wherein the integrated thermal management valve has a thermostat mounted thereto;
• a radiator connected with the integrated thermal management valve and the coolant pump;
• a controller controlling operations of the integrated thermal management valve,
• wherein the thermostat comprises:
• a thermostat housing having an inlet and an outlet;
• an internal housing having a main valve hole and a fail-safe hole, wherein the internal housing is disposed within the thermostat housing and has a main chamber, which communicates with the inlet of the thermostat housing, therein;
• a wax housing disposed within the internal housing and having a first wax and a second wax;
• a first valve selectively opening or closing the main valve hole according to expansion or shrink of the first wax;
• a second valve selectively opening or closing the fail-safe hole according to expansion or shrink of the second wax;
• an electric heater configured to selectively expand the first wax;
• and
• a coolant passage, through which coolant flowing through the fail-safe hole flows out to the outlet of the thermostat housing, defined between the thermostat housing and the internal housing.