State GPG 81 370NEA - Manual (Page 50)

50
manifold kits
Dimensions shown are for minimum space occupied by the water heaters
assemblies.
Space for the barometric draft control assemblies, combustion clearances
and servicing must be added.
prior to start up
important
Factory Start-up is required for activating warranty and assuring maximum
operating performance. Contact your local sales representatives or
Authorized Start-up Agent to arrange a Free Certified Start-up.