A. O. Smith ATHR-160M 1 vs American ATHR-180M 1 (MTHR-180M 1)

Both water heaters carry the same efficiency rating: UEF 0.95. The American ATHR-180M 1 (MTHR-180M 1) sustains the higher flow (5.3 GPM vs 4.8 GPM under the DOE test).

A. O. Smith ATHR-160M 1 American ATHR-180M 1 (MTHR-180M 1)
Uniform Energy Factor (UEF) 0.95 0.95
Fuel Natural Gas, Propane Natural Gas, Propane
Max flow rate 4.8 GPM 5.3 GPM
Draw pattern High High
Annual gas use (natural gas) 178 therms/yr 178 therms/yr
Gas input rate 160 kBTU/h 180 kBTU/h
Max current draw 5 A 5 A
Vent type Power Vent, Power Direct Vent Power Vent, Power Direct Vent
Recovery efficiency 98 % 97 %
Smart / connected capable No No
Minimum activation flow 1 GPM 1 GPM
Annual propane use 194.53 gal/yr 194.53 gal/yr
Vent size 3 / 2 3 / 2
Width 17 in 17 in
Depth 16 in 16 in
ENERGY STAR certified Yes Yes

Frequently asked questions

Which costs less to run, the A. O. Smith ATHR-160M 1 or the American ATHR-180M 1 (MTHR-180M 1)?

They are effectively tied: both cost about $258/year at national average energy rates under the DOE test draw pattern.

Are the A. O. Smith ATHR-160M 1 and American ATHR-180M 1 (MTHR-180M 1) both ENERGY STAR certified?

Yes — every water heater in this database is drawn from the U.S. EPA ENERGY STAR certified water heater datasets.