One's problem with five kilns (5)
I believe the answer is:
ovens
'kilns' is the definition.
(I've seen this in another clue)
'one's problem with five' is the wordplay.
'problem with' is an anagram indicator.
'five' becomes 'V' (Roman numeral).
'ones' anagrammed with 'v' gives 'OVENS'.
(Other definitions for ovens that I've seen before include "Cooking equipment" , "In which to bake or roast" , "Appliances for baking or roasting" , "Kitchen appliances" , "Kilns or stoves" .)