10.9   Water Heater Installation

Follow these procedures when installing a storage water heater or an alternative water heater.

ü       Replacement water heater must have a pressure-and-tem­perature relief valve with a discharge line that terminates less than 6 inches from the floor into a floor drain or drain pan.

ü       The discharge pipe should be made of rigid metal pipe or approved high-temperature plastic pipe.

ü       Install dielectric unions and a backflow preventer as part of a water heater replacement if any of these components are missing from the existing installation.

ü       Install an expansion tank for all storage water-heater replacements.

ü       Install an emergency drain pan under each replacement water heater that is installed in an area that would be dam­aged by a leak.

ü       Install a ³/₄-inch drain line to the tapping on drain pan. Terminate the drain line in a floor drain or outdoors, at least 6 inches above grade.

ü       Install heat traps on the water heater’s inlet and outlet pip­ing if the manufacturer hasn’t provided traps.

ü       Adjust water temperature to 120° F or to the lowest setting acceptable to occupants.

For a complete list of DOE installation requirements for water heaters, see SWS Detail 7.8102.2 Storage-Type Appliance.