Smoke director (4)
I believe the answer is:
flue
'smoke director' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for flue that I've seen before include "Air vent" , "Duct for smoke/gases" , "Outlet for smoke or gas" , "Vent pipe for smoke, etc" , "Fuel (anag.)" .)