Fire clearly relates to work as well
Exodus 35:1-3 1. Moses called the whole community of the children of Israel to assemble, and he said to them: "These are the things that the Lord commanded to make. 2. Six days work may be done, but on the seventh day you shall have sanctity, a day of complete rest to the Lord; whoever performs work thereon [on this day] shall be put to death. 3. You shall not kindle fire in any of your dwelling places on the Sabbath day."
What exactly does the verb "kindle" mean in the original Hebrew? Does it refer to any act of adding fuel to a fire, or only to the act of lighting fire "from scratch", or what? Would it be acceptable to take out of a fire a stick whose end was in the fire, and then carry it as a torch? Unless the the addition of any fuel to a fire is a violation, I don't really see any clear line which would be violated by turning on the burner of an old-style (pilot-based) stove since that merely extends the fuel supply of an already-existing fire.