Heater Blowing, but no hot air...?

Grab the heater lines to the core and see if they're hot. Open the radiator cap, not the overflow tank, and make sure you have all of the air out of the system. Those Buicks have bleed valves on the thermostat housing. Take the heater core lines off and try to blow it out with a garden hose. Dexcool has clogged up lots of GM cores.

find the heater valve near the fire wall, it could be vacuum operated if so make sure it has a good seal at the vacuum connector or that the skinny tube is holding a vacuum.

if there is no vacuum to operate4d the heater valve it will not allow hot water?antifreeze to flow through the climate system.

if the valve is cable operated you can manually open it by twisting a small lever that sits on top of the valve.

have someone who knows how to fix vacuum leaks inspect the car. it could be that simple, it could also be that when working on the car, a vacuum hose got disconnected by accident, in which case all you need to do is to plug it back again to the corresponding plug.

gl

coolant full ??....................air bubble in system ??