If reservoir level up, does it overflows?
Open up the radiator cap n see the water level inside when engine is cooled. If no water, or dropped in water level inside, it may indicate burnt head gasket o even cracked engine head.

U should see water once u open the radiator cap. If can't see water, then u have a problem.
While u r at it, check your engine oil level. Low engine oil level will cause engine overheating (or running hotter than normal), and water from radiator will go to reservoir tank.

This post has been edited by ahsam1212: Jan 18 2017, 12:26 PM