Water Heater Brochure

A. O. Smith tankless water heaters can be used in a wide variety of applications. Whether used in recirculation
systems, in conjunction with storage tanks or with heating applications, our commercial units are built to provide
continuous hot water when sized appropriately for your home’s needs.
Local codes dictate proper compliance.
Basic Installation
(excluding 540P)
540P Basic Installation
(Models with integrated recirculation only)
All application diagrams shown are concept drawings only. These diagrams are only to be used as basic guides. It is up to the application designer to properly design the plumbing layout and correctly size
all components within an application (pumps, piping, storage tanks, water heaters, etc.). All national and local codes must be followed and will dictate proper compliance.
Hot Water to Fixtures
Hot Water Return
Gas Supply
Cold Water Supply
Expansion Tank
1. Recirculation pump shall be sized for 2-4 gpm per activated heater (4-8 gpm for 910)
2. Recirculation pump shall be controlled by an aquastat. The minimum suggested differential should be 10°F
3. For installations without recirculation, remove the check valves, pump, and aquastat.
TANKLESS APPLICATION DIAGRAMS
Legend
Pump Shut Off / Isolation Valves Pressure Relief Valve Air Vent Aquastat Check Valve Full Port Ball Valve
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