Sudden switching of power on without gas hit production (4,2,7)
I believe the answer is:
coup de theatre
'production' is the definition.
(coup de theatre is a kind of production)
'sudden switching of power on without gas hit' is the wordplay.
I cannot quite understand how this works, but
'of' could be 'o' and 'o' is found in the answer.
'power' could be 'heat' (heat is a kind of power) and 'heat' is located in the answer.
'on' could be 're' (regarding) and 're' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for coup de theatre that I've seen before include "sensational twist" , "moment of drama" .)