Hit the roof (3,3)
I believe the answer is:
see red
'hit the roof' is the definition.
(both can mean to become very angry)
This is all the clue.
(Other definitions for see red that I've seen before include "Be annoyed" , "Become angry as bull might" , "Lose temper like angry bull" , "Burst a blood vessel" , "Become angry (colloq.)" .)