If you have an existing water heater in a confined space, or that has a doorway to access the water heater which the water heater barely fits through now, perhaps a water heater in the attic, under an Air Conditioner, or built into the cabinetry of your closet, please read and take action if necessary.
The new water heaters will be two inches larger in diameter and two inches taller than your exiting heater. If you own a water heater that is installed in one of these above mentioned applications or similar, you may want to consider replacing the heater. Because of the new sizes, you may have to replace your existing water heater with a smaller water heater in order to install it in the same location as the existing water heater. Of course this means less hot water available for you to use.
Please replace your water heater if needed, while supplies last.