Overheating

Air in system bleed air from system like this remove cap from overflow tank fill with antifreeze to full mark leave cap off and start vehicle and let idle you will notice level in tank start to rise this is normal once thermostat starts to open level in tank will drop add more antifreeze to full mark then put cap back on.

Then use the bleeder valve next to the thermostat to bleed of any remaining trapped air. This whole process works better if the car is parked facing uphill.

Either has air in the system or the thermostat was installed backwards.