Ford Taurus Heater Smell

I Have A 2001 Ford Taurus. I Had The Head Gaskets Changed, The Radiator, The Thermostat 3x's And The Hearter Coil. The Over Heating...

Coolant Looked Dirty And Low, So I Filled It Up To Cool Line With 50/50 Green Coolant. When Hot, Coolant Overflowed Out Of Reservoir Lid....

The Heater Gets Warm But Never Hot, And Always Smells Like Burnig Antifreeze Is This A Broken Gaskett Seal? Or Could It Be Something Else?

I Can Smell Antifreeze When I Have The Heater On, Could Someone Tell Me What This Might Be Thanks