In this video, This Old House plumbing and heating expert Richard Trethewey explains how new energy-saving regulations affect today's water heaters.
1. Small-capacity gas-fired water heaters, in the 30-gallon to 50-gallon range, must now have at least 2 inches of insulation on the sidewalls of the tank and 2 to 4 inches at the top of the tank.
2. Gas-fired water heaters with 55-gallon or larger tanks can no longer be vented into a chimney.
3. New condensing water heaters must be connected to a PVC vent and direct-vented to the outdoors.
4. The new electric-powered water heaters with 55-gallon and larger tanks will be hybrid heat pumps that use 50 percent less energy but are much larger and taller than previous units.
5. The new regulations don't affect on-demand tankless water heaters.