If the engine is heating to normal temp then you may have an air lock going to the heater. You may have bleeder screws in the system to bleed the air out you'll have to look around. Your heater could be partiallly plugged as well. Best way to cure that is to back flush the heater core with water. Of course before you do all of htat, make sure that both heater hoses are approximately the same temp. If they are then it's not the cooling system it is probably an air delivery problem. Also check your radiator cap as that is the most overlooked part on the coolant system.