pilot light — Also called pilot, pilot burner. a small flame kept burning continuously, as in a gas stove or furnace, to relight the main gas burners whenever necessary or desired.
boiler — A boiler is a device which burns gas, oil, electricity, or coal in order to provide hot water, especially for the central heating in a building.
fastball — a pitch thrown at or near a pitcher's maximum velocity.
furnace — a structure or apparatus in which heat may be generated, as for heating houses, smelting ores, or producing steam.
oven — a chamber or compartment, as in a stove, for baking, roasting, heating, drying, etc.