Family installing large oven (4)
I believe the answer is:
kiln
'oven' is the definition.
(I know that kiln is a type of oven)
'family installing large' is the wordplay.
'family' becomes 'kin' (synonyms).
'installing' is an insertion indicator (inserted letters are installed).
'large' becomes 'L' (eg in clothes sizes).
'kin' going around 'l' is 'KILN'.
(Other definitions for kiln that I've seen before include "Furnace, oven" , "Oven for firing pottery" , "Potter's furnace" , "Industrial furnace" , "Large commercial oven" .)