Congress is voting to cancel a Department of Energy rule that would have required gas-powered tankless water heaters (the kind that heat water on demand instead of storing it in a tank) to meet stricter energy-efficiency standards starting soon. If this resolution passes, that rule never takes effect, meaning manufacturers won't have to redesign these water heaters to use less energy, and the older, less efficient standards stay in place instead. This mainly affects homeowners buying new gas tankless water heaters and the companies that make and sell them.