Incinerator's features including receptacle for ashes (7)
I believe the answer is:
furnace
'incinerator's' is the definition.
(I've seen this before)
'features including receptacle for ashes' is the wordplay.
'features' becomes 'face'.
'including' means one lot of letters goes inside another.
'receptacle for ashes' becomes 'urn' (ashes are typically stored in an urn).
'face' enclosing 'urn' is 'FURNACE'.
(Other definitions for furnace that I've seen before include "Enclosed chamber to produce heat" , "Fiery chamber" , "Chamber for heating minerals or metals" , "cooker" , "High-temperature oven" .)