More detailed info on NAECA 2015 Water Heater Changes (PDF)

As of April 2015, the NAECA has adopted new regulations for water heaters. This means that all residential water heaters that were manufactured in the United States, must meet specific NAECA energy-efficiency standards.

If you have a 75 gallon gas water heater and it fails, you will not be able to replace it with a similar unit. Your options will include installing a power vented, condensing unit at roughly DOUBLE the cost or installing multiple smaller capacity units.

If you have an electric water heater larger than 55 gallons, you will not be able to replace it with a similar unit. Your options include installing a hybrid electric heat pump water heater at roughly DOUBLE the cost or installing multiple smaller capacity units.

All water heaters will now be taller and wider to accommodate increased insulation to meet efficiency standards. If you have space limitations, an identical gallon capacity replacement unit may not fit.

Initial estimates predict at least a 30% increase in ALL water heaters.

More about these NAECA regulations can be found at http://www.bradfordwhite.com/naeca and http://www.hotwater.com/naeca/