Hot wire warmer (6)
I believe the answer is:
hearth
'warmer' is the definition.
(hearth is a fireplace)
'hot wire' is the wordplay.
'hot' becomes 'h' (abbreviation eg on taps).
'wire' becomes 'earth' (an earth or ground wire in electronics).
'h'+'earth'='HEARTH'
(Other definitions for hearth that I've seen before include "where the home is built?" , "cosy setting" , "Area around the fire" , "Novel" , "suitable place for a fire" .)