Stoker's anger minutes after breaking cooling device (7)
I believe the answer is:
'stoker's' is the definition.
'anger minutes after breaking cooling device' is the wordplay.
'anger' becomes 'ire' (ire is intense rage).
'minutes' becomes 'm' (common abbreviation).
'after' is a charade indicator (letters next to each other).
'breaking' means one lot of letters goes inside another.
'cooling device' becomes 'fan' (I've seen this before).
'irem' inserted within 'fan' is 'FIREMAN'.
(Other definitions for fireman that I've seen before include "Red engine driver" , "Fighter of blaze" , "Railway driver's assistant" , "Chap with a ladder and hose" , "he puts out at work" .)