The smell of rotten eggs in the air, unlike stinky water, indicates a gas or methane leak. Gas leaks in your home can be dangerous. Not only that, but it is harmful to the environment. A 2019 study found that 58 million gas water heaters in the United States emit 91,000 tonnes of methane into the atmosphere. Open all windows to allow air circulation if there is a leak. You should relight your pilot lights.