A.O. Smith ATI-305-N User manual

Each A. O. Smith on-demand water heater is designed for a
specific application. Consult your sales representative or contact
A. O. Smith for specifications and recommendations on which
model is right for specific requirements.
A. O. Smith On-Demand
Gas Water Heaters
BTU Input Approximate
Model Natural / Propane Hot Water Output (GPM) Shipping
Number Minimum Maximum Maximum 45º F Rise 77º F Rise Weight (lbs)
INDOOR MODELS
ATI-305N 15,000 199,000/190,000 5.3 5.3 4.2 50
ATI-505N 15,000 199,000/190,000 8.5 7.4/7.1 4.2 50
ATI-705N 19,000 237,000 9.8 8.8 5.1 55
ATI-705AN* 19,000 237,000 9.8 8.8 5.1 55
OUTDOOR MODELS
ATO-305N 15,000 199,000 5.3 5.3 4.2 50
ATO-505N 15,000 199,000 8.5 7.3 4.2 50
ATO-705N 19,000 237,000 9.8 8.7 5.1 55
ATO-705AN* 19,000 237,000 9.8 8.7 5.1 55
* 705A models are ASME Certified.
For propane, change “N” to “P” in model number (ATI-305P).
Model Specifications
AMGBROO107 ©2007 A. O. Smith Corporation A. O. Smith reserves the right to make product changes or improvements at any time without notice. Printed in U.S.A
January 2008R
500 Tennessee Waltz Parkway •Ashland City, TN 37015
www.hotwater.com
INNOVATION ON DEMAND
A. O. Smith’s complete line of tankless gas water heaters
September2008R
201866 AMGBR00107 1201866 AMGBR00107 1 9/10/08 11:38:54 AM9/10/08 11:38:54 AM

Model Selection Guide
1 305 or 505 305 or 505 305 or 505
2 305 or 505 305 or 505 305 or 505
3 505 or 705 (2) 505 or 705 (2) 505
4 (2) 505 (2) 505 (2) 505
5 (2) 505 (2) 705 (2) 705
6 or more Multi-system Multi-system Multi-system
*Note: This selection guide is based on 120°F outlet water temperature.
Ground water
temperature factor.
The temperature of incoming
ground water (cold water inlet
temperature) varies greatly
throughout the U.S. and also
fluctuates with change of season.
The temperature of water as it
enters the water heater will
determine the amount of
“temperature rise” required to
achieve the desired hot water
outlet temperature (120°F is
recommended).
The best way to measure your
incoming ground water temperature
is to use a thermometer to measure
cold water temperature during the
coldest season of the year. To
simplify the process, use this map to
determine whether your installation
location is in the Southern Zone,
Central Zone or Northern Zone.
Peak hot water demand.
The next step is to determine how
much hot water will be required
during the busiest usage period
(“peak demand”). To use the chart,
consider all appliances and fixtures
that use hot water including
lavatory faucets, kitchen faucets,
washing machines, dishwashers,
showers and bathtubs. Be sure to
determine how many appliances
and fixtures will be used at the
same time (“peak demand”).
Average Ground Water Temperatures
SOUTHERN ZONE
Average Ground Water
Temperature: 62°F to 77°F
CENTRAL ZONE
Average Ground Water
Temperature: 52°F to 61°F
NORTHERN ZONE
Average Ground Water
Temperature: 37°F to 51°F
Ground Water Temperature Zone
Appliances or fixtures
in simultaneous use
during peak demand
A. O. Smith On-Demand
Gas Water Heaters
Remote
Controller
All models come with a
Remote controller that
can set the temperature
within a specific range.
In Use Indicator Light
Indicates hot water is being supplied
(a tap is open)
Priority Indicator
Indicates that this controller is
setting the temperature
Priority Button
Priority can be changed to another
controller if desired
On/Off Button
Will turn the water heater on/off
Temperature Display
Shows the temp setting
Error Codes
When a fault is detected an error code
flashes at the temperature setting
Thermostat
Increases/decreases temp setting
Product Features:
Commercial
Application Features:
Endless Hot Water. Endless Innovation.
Trust the innovation leader to give
you more choices in on-demand water
heating. A. O. Smith’s comprehensive
line supplies endless hot water when
you ask for it...with high efficiency that
saves money on both residential and
commercial applications.
Innovative Technology
■Indoor and outdoor installation options
■ Continuous hot water on demand
(up to 9.8 GPM)
■Whole house water heating solution
■Direct electronic ignition –
no pilot light
■On-board diagnostics and
safety monitoring
■Interior sealed combustion
(does not use interior combustion air)
■Applicable for residential hydronic
heating applications
Excellent Performance
■12-year limited warranty on
heat exchanger, 5-year warranty
on all parts
■Can be installed outdoors, saving
valuable indoor square footage
Energy Efficiency
■Up to 84% thermal efficiency,
providing significant energy
cost savings
Sleek Design
■Smooth pleasant lines and
rounded corners
■Matching pipe cover available
for finished appearance
• ASME Certified
• Hot water capacity of 0.6 – 9.8 GPM
• Min. – Max. input: 19,000 – 237,000 BTU
• Max. temperature: 185°F with
Commercial Controller
• Ideal for small restaurants, multifamily
housing, hair salons and spas,
laundromats, car washes and other
limited commercial needs
Southern Zone Central Zone Northern Zone
201866 AMGBR00107 2201866 AMGBR00107 2 9/10/08 11:39:01 AM9/10/08 11:39:01 AM