Mr.xtype, I would say yes, trapped air in system will cause fans to turn on, but I would check your hoses to make sure your heated fluid is being transferred from your water pump or thermostat. If all your hoses are cool but your engine is hot, then your water pump is number one suspect. But for you problem, just keep cooling and adding antifreeze as the water pump pumps the fluid and ejects the air. should be okay after two or three tries. If not, then check your water pump.