Hot Water List
Menu

American ATI-180B-N 1**

American ATI-180B-N 1** is in the DOE listing as of Oct 19, 2026.

  • Gas tankless water heater
  • 2 listed models

Not listed as ENERGY STAR certified on Oct 19, 2026.

Its figures are also listed under A. O. Smith ATI-180B-N 1**.

Flow at a 67°F rise
4.7gallons per minuteCertified
Advertised flow
10.5gallons per minuteAmerican, no rise stated
UEF
0.82Uniform energy factor
See it among every gas tankless model

Flow where you live

Colder incoming water needs a bigger rise, so the heater gives less flow.

Cold water
Cold water must be at least 10°F colder than the hot water setting.
Flow estimate
The estimate uses the lowest certified flow among the listed models. It is about 4.5 gal/min at a 70°F rise.

Flow limits

  • The estimate excludes the flow needed to turn the heater on, heat lost in pipes, and installation.
  • Cold water from a well or long pipe run can differ from the temperature you enter.
  • Without a stated flow limit, estimates for warmer water may exceed the heater’s actual flow.

Advertised and certified figures

American ATI-180B-N 1**: advertised and certified
American ATI-180B-N 1**: advertised and certified UEF: advertised 0.82, certified 0.82. Flow: advertised 10.5 gal/min, certified 4.7 gal/min (advertised no rise stated, certified at a 67°F rise). Flow: advertised 4.7 gal/min, certified 4.7 gal/min (advertised at a 67°F rise, certified at a 67°F rise). UEF Advertised 0.82 Certified 0.82 Flow · advertised no rise stated, certified at a 67°F rise Advertised 10.5 gal/min Certified 4.7 gal/min Flow · advertised at a 67°F rise, certified at a 67°F rise Advertised 4.7 gal/min Certified 4.7 gal/min
FigureAdvertisedCertifiedAdvertiserRead
UEF 0.82 0.82 American Read Oct 4, 2026
Flow 10.5 gal/min, no rise stated 4.7 gal/min at a 67°F rise American Read Oct 4, 2026
Flow 4.7 gal/min at a 67°F rise 4.7 gal/min at a 67°F rise American Read Oct 4, 2026

See how advertised flow compares across tankless models

Certified figures by listed model

Model numberUEFFlow at a 67°F rise (gal/min)Recovery efficiencyDraw pattern
MTI-180B-N 1**0.824.784%High
MTI-180X3-N 1**0.824.784%High

UEF is the uniform energy factor. A dash means the model has no such figure.

It warms 4.7 gallons per minute of water from 58°F to 125°F in the test. The median gas tankless model heats 4.8 gallons per minute by 67°F. Of 487 gas tankless models, 252 have a higher flow than this one.

It was not listed as ENERGY STAR certified on Oct 19, 2026. In the test, 18% of its energy does not reach the hot water (UEF 0.82). The daily hot water use in the test, called its draw pattern, was high. Its UEF is lower than that of 243 of the 399 gas tankless models with its draw pattern. For its type and draw pattern, the median UEF is 0.93. Of the energy it spends heating water, 84% ends up in it (its recovery efficiency).

It is the basic model for MTI-180B-N 1** and MTI-180X3-N 1**. All of its test figures are shared by 6 other basic models. Each of the 6 other brands lists one of them. For the full group, see the A. O. Smith ATI-180B-N 1**.

It may qualify for one rebate program if it meets their other terms.

Also listed as

They carry every figure in the table above.

Rebates

ProgramStateStatusProgram page
SoCalGas High-Efficiency or ENERGY STAR Certified Natural Gas Tankless Water Heaters rebate CA May qualify if it meets the other terms Its own page

Programs change their terms. Check the program's own page before you buy.

Updated Oct 19, 2026 · Methodology

Not covered

  • Changes to an advertised figure after the date beside it.