Specification Sheet

ManualsBrandsAO Smith ManualsResidential Tankless Water HeatersAO Smith 10 GPM Residential/Commercial Condensing Natural Gas Indoor Tankless Water Heater with 199000 Maximum BTU Input

Residential / Commercial Gas

Tankless Water Heaters

www.hotwater.com | 800-527-1953 Toll-Free USA | A. O. Smith Corporation | 500 Tennessee Waltz Parkway | Ashland City, TN 37015

FEATURES:

CONTINUOUS MAXIMUM FLOW

RATES UP TO 10.0 GPM

ENERGY STAR

QUALIFIED

AVAILABLE IN NATURAL GAS OR

PROPANE (LP)

540 MODELS

• Can be used in residential and commercial

applications

• Easy-link up to 4 heaters

• Multi-link up to 20 heaters

INDOOR MODEL

• Includes integrated temperature controls

and advanced diagnostics to simplify

troubleshooting

• Factory-installed power cord

OUTDOOR MODEL

• Includes a wall mount temperature remote

controller and advanced diagnostics to

simplify troubleshooting

DURABLE HEAT EXCHANGER:

• Primary heat exchanger is constructed of

a commercial-grade copper that is more

resilient to erosion. Copper is 25x better

at heat transfer than stainless steel thus

stabilizing outgoing water temperatures

quicker.

• Secondary Heat Exchanger is made of Type

316L Stainless Steel to protect against

corrosion.

COMMON VENT UP TO 8 UNITS

COMPLIES WITH LEAD FREE

STANDARDS

SAFETY FEATURES:

• Air-Fuel Ratio (AFR) Sensor

• Exhaust & Water Temperature Safety

Control

• Overheat Cut-Off Fuse

INTERNAL FREEZE PROTECTION

SYSTEM

POWER DIRECT VENT DESIGN

• Category III or IV venting can be used

• Exhaust, 3” PVC Venting up to 70 Feet or

4” PVC Venting up to 100 Feet

• Provides ﬂexible venting with PVC, CPVC,

or ABS Pipe for Intake and Exhaust (solid

core only). Canadian Installations Require

ULCS636 Listed PVC or CPVC Pipe for

Venting.

ACCESSORIES

• Pipe Cover

• Neutralizer Kit

• Isolation Valve Kits

• Concentric Termination

• Product Preservers

Anti-Scale System

• Multi-Unit Controller (540 Model Only)

• Commercial Remote Temperature Control

(540 Model Only)

WARRANTY

• 15-year limited warranty on heat exchanger

in residential applications

• 6-year limited warranty on heat exchanger

in commercial applications

• 5-year warranty on all parts

TANKLESS HIGH EFFICIENCY

CONDENSING WATER HEATERS

Page 1 of 6

AOSRG46835

INDOOR MODELS

ATI-240, ATI-340, ATI-540

OUTDOOR MODELS

ATO-240, ATO-340, ATO-540

Ultra-Low NOx gas tankless water heaters with condensing technology featuring

an unprecedented 0.95 Energy Factor which lowers operating costs and is

environmentally friendly.

ANSI Z21.10.3 CSA 4.3

540 models

only

Summary of content (6 pages)

PAGE 1
Residential / Commercial Gas Tankless Water Heaters TANKLESS HIGH EFFICIENCY CONDENSING WATER HEATERS INDOOR MODELS ATI-240, ATI-340, ATI-540 Ultra-Low NOx gas tankless water heaters with condensing technology featuring an unprecedented 0.95 Energy Factor which lowers operating costs and is environmentally friendly. FEATURES: SAFETY FEATURES: CONTINUOUS MAXIMUM FLOW RATES UP TO 10.
PAGE 2
Residential / Commercial Gas Tankless Water Heaters TANKLESS HIGH EFFICIENCY CONDENSING MODELS Gas Consumption Input Model Number Inlet Gas Pressure Dimensions in Inches Energy Maximum Hot/Cold Unit Gas Factor Weight Minimum Maximum GPM* Connections Connection Height Width Depth (lbs) (EF) in. W.C. in. W.C. Type Minimum BTU/H Maximum BTU/H Natural Propane Natural Propane Natural Propane 15,000 13,000 15,000 13,000 15,000 13,000 160,000 160,000 180,000 180,000 199,000 199,000 4.0 8.0 4.0 8.0 4.0 8.
PAGE 3
Residential / Commercial Gas Tankless Water Heaters INDOOR MODEL INDOOR MODEL 11-1/4" (285 mm) 4" (101 mm) 4" (102 mm) Female 5-3/4" (147 mm) Exhaust 2-5/8" (65 mm) 4" (102 mm) Female 22-1/2" (570 mm) 23-5/8" (600 mm) 24-7/8" (631 mm) 6-1/4" (159mm) Intake 2-5/8" (68 mm) 17-3/4" (450 mm) 7" (180 mm) 10-3/4" (272mm) Condens ate drain port 7-1/2" (189 mm) GAS 5-7/8" (147 mm) 120 VAC 3" (77 mm) COLD 5/8" (17 mm) 5-3/4" (147 mm) Condensate drain port 7-7/8" (199 mm) 17-5/8" (448 mm) COLD 6-3/4"
PAGE 4
Residential / Commercial Gas Tankless Water Heaters OUTDOOR MODEL OUTDOOR MODEL 17-3/4" (450 mm) 7" (180 mm) 11-1/4" (285 mm) 11" (281 mm) 22-1/2" (570 mm) 3-5/8" (92 mm) 1-1/2" (37 mm) 23-5/8" (600 mm) 24-7/8" (631 mm) 4-1/2" (114 mm) 10-3/4" (272 mm) HOT 4-3/4" (120 mm) 120 VAC 6-1/4" (159 mm) Drain port 6-3/4" (170 mm) COLD 5/8" (17 mm) GAS 5-3/4" (147 mm) Condens ate drain port 7-1/2" (189 mm) 1/2" (13 mm) 120 VAC 3" (77 mm) GAS (131 mm) HOT (140 mm) Drain port 6" (152 mm) COLD 6-3/4" (172 mm)
PAGE 5
Residential / Commercial Gas Tankless Water Heaters FLOW RATE vs TEMPERATURE RISE FLOW RATE vs TEMPERATURE RISE 240H 340H Flow Rate vs. Temperature Rise 10 .0 9.0 9.0 8.0 8.0 7.0 7.0 Flow Rate (GPM) 10 .0 Flow Rate (GPM) 11.0 11.0 6.0 5.0 4.0 3.0 Flow Rate vs. Temperature Rise 6.0 5.0 4.0 3.0 2.0 2.0 1.0 1.0 0.0 0.0 0 20 40 60 80 0 100 20 Temperature Rise (°F) 40 60 100 80 Temperature Rise (°F) 540H Flow Rate vs. Temperature Rise 11.0 10 .0 9.0 8.0 Flow Rate (GPM) 7.0 6.
PAGE 6
Residential / Commercial Gas Tankless Water Heaters SUGGESTED SPECIFICATION FOR ATI-540H OR ATO-540H The fully modulating, on-demand, condensing gas fired tankless water heater(s) shall be A. O. Smith Tankless Water Heater model ATI-540H or ATO-540H, having a maximum input rating of 199,000 Btu/h and available in NG or LP. The heater shall have ¾ in. male NPT water and gas connections. The inlet gas supply pressures shall be 4.0 in. WC (min.) up to 10.5 in. WC (max.) for NG and 8.0 in. WC (min.