Fuel required for heating a stove (3)
I believe the answer is:
gas
'fuel' is the definition.
(gas is a fuel)
'required for heating a stove' is the wordplay.
'required for' indicates a hidden word.
'GAS' is hidden in the letters of 'heating a stove'.
(Other definitions for gas that I've seen before include "Form of fossil fuel" , "Substance like air" , "Eg, nitrogen" , "THIRD PART OF 23" , "Americans' petrol" .)