what grain of truth says. The heater core is usually the highest point in the cooling system. You still have air in the system and your heater core doesn't get enough coolant to heat. All the air is in the core.
...and radiator. Still nothing? It blows air but it is hardly even warm. It is about luke warm I would say and we don't know what to do. Could it be the water pump? Any suggestions or help would be great