Pilot Light (Fallout 3)

The pilot light is a miscellaneous item in Fallout 3 and Fallout: New Vegas.

Uses
In Fallout 3, one is needed in the creation of a Shishkebab and as Rock-It Launcher ammunition. In Fallout: New Vegas with the Dead Money add-on installed, one is required to craft a gas bomb and the super heated cosmic knife.

Fallout 3
They're frequently found in ovens (found in many abandoned houses, for instance in Minefield), or in workshops. A pilot light can be obtained early in the game by searching through Silver's stove inside her house in Springvale, in the Super-Duper Mart in the back room, or in the RobCo facility.

Fallout: New Vegas
Similar to Fallout 3, pilot lights in Fallout: New Vegas can be found in ovens. Many can be found in the basement of the REPCONN test site, especially in the storage room in the southwest. There are also several of them lying on the floor across the whole basement.
 * Seven can be found in Novac near the gas station, on top of the shelves
 * Five in the train tunnel.
 * Four in the Gomorrah suites.
 * Four in Cerulean Robotics in Freeside.
 * Three at Zapp's Neon Signs in the South Vegas ruins.
 * One can be found in a Nelson house.
 * In the oven of Jeannie May Crawford's house in Novac.
 * One can be found in an oven in Fields' shack.
 * In an oven inside a Goodsprings home.
 * Can be found in the ovens in the Lucky 38 presidential suite.
 * One can be found on a table in Raul’s Shack