Pilot light

llama piloto | lamparilla (estufas, calentadores, etc.) | luz indicadora (comunicaciones) | luz de aviso de piloto (navegación aérea)

(n.) = piloto, luz piloto, testigo luminoso, llama piloto
Ex: The problem with pilot lights is that they waste a lot of gas and that's why most modern appliances do not have them.

SPA: Piloto
A small, continuous flame (in a hot water heater, boiler, or furnace) that ignites gas or oil burners when needed.