Painter I brought in to supply bathroom fitting (5,4)
I believe the answer is:
towel rail
'bathroom fitting' is the definition.
(railing for towels fitted in a bathroom)
'painter i brought in to supply' is the wordplay.
'painter' becomes 'ra'.
'brought in' is an insertion indicator.
'supply' becomes 'well' (well can mean a supply or reservoir).
'ra'+'i'='rai'
'to'+'well'='towell'
'rai' inserted inside 'towell' is 'TOWEL-RAIL'.
(Other definitions for towel rail that I've seen before include "Bathroom supporter" , "support for drying out?" .)