Product Overview
TANKLESS
RESIDENTIAL GAS WATER HEATERS
A. O. Smith tankless water heaters are designed to
give you continuous* hot water while helping you
save money. Heating water only when you’re using it,
A. O. Smith models incur no standby energy losses,
providing efficient heating while conserving energy.
They also provide great peak-time flexibility for
households with multiple members—no more worries
about staggering showers or delaying laundry.
A. O. Smith tankless water heaters take up much
less space than conventional tank-type water heaters
or boilers, utilizing a wall mount design that allows
for additional storage and flexibility. With durable,
commercial-grade parts, A. O. Smith water heaters are
built to deliver reliable performance year after year.
*When sized appropriately for your home’s needs.
• Category III stainless steel wenting
• Complies with Ultra-Low NOx regulations
• Indoor models have integrated controls and diagnostics
• Outdoor models include remote control as a standard feature
• Gas convertible from natural gas to propane using supplied kit
• 15-year limited residential heat exchanger warranty
• 5-year limited commercial heat exchanger warranty
• 5-year limited parts warranty
A. O. Smith | hotwater.com
500 Tennessee Waltz Parkway | Ashland City, TN 37015 | 800.527.1953
AOSBG01000 | © March 2020 A. O. Smith Corporation | Printed in U.S.A.
THE SMARTER
WAY TO
HEAT WATER
NON-CONDENSING
ULTRA-LOW NOX
Model
Number*
Type
BTU/h Input Natural
UEF
Minimum Maximum
ATI-110U Indoor 15,000 140,000 0.81
ATI-310U Indoor 15,000 190,000 0.81
ATI-510U Indoor 15,000 199,000 0.81
ATI-110U Outdoor 15,000 140,000 0.81
ATI-310U Outdoor 15,000 190,000 0.81
ATI-510U Outdoor 15,000 199,000 0.81
Model
Number*
Hot Water Output (GPM)
Unit
Weight
(lbs.)
Maximum 45°F Rise 70°F Rise
ATI-110U 6.6 5.1 3.3 37
ATI-310U 8.0 6.9 4.4 37
ATI-510U 10.0 7.2 4.7 39
ATI-110U 6.6 5.1 3.3 37
ATI-310U 8.0 6.9 4.4 37
ATI-510U 10.0 7.2 4.7 39
*Units are field convertible from natural gas to propane with supplied conversion kit.