[Lynn]

I'm going to make the assumption that the heater lines come off of the radiator lines once they reach the front of the car, one before the radiator and one after it. If this is not the case, then, in the words of Rose Ann Rosanadana, never mind.

Otherwise, with the engine running and heater on, try pinching off the radiator line between the inlet heater hose and the radiator for a bit to force more water through the heater core to clear any air lock. Not saying that you shouldn't put a valve to release air during fillup mind you.