Shawl put back when central heating used, at first (5)
I believe the answer is:
fichu
'shawl' is the definition.
(I've seen this before)
'back when central heating used at first' is the wordplay.
'back' is a reversal indicator.
'when' becomes 'if'.
'central heating' becomes 'ch'.
'at first' says to take the initial letters.
The first letter of 'used' is 'u'.
'if' back-to-front is 'fi'.
'fi'+'ch'+'u'='FICHU'
'put' acts as a link.
(Other definitions for fichu that I've seen before include "Woman's small shawl or scarf" , "Triangular piece of muslin for the neck" , "Lace shawl" , "Small triangular shawl" , "old-fashioned cape" .)