The Collaborative International Dictionary of English v.0.48:

oil heater \oil heater\, oil-heater \oil-heater\n.
   A heating or cooking device that burns oil (such as kerosine)
   as a fuel.

   Syn: oilstove, kerosene heater, kerosine heater.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

oil heater
    n 1: heater that burns oil (as kerosine) for heating or cooking
         [syn: oil heater, oilstove, kerosene heater,
         kerosine heater]