American ATHR-160M 1 (MTHR-160X3 1)

American ATHR-160M 1 (MTHR-160X3 1) is a gas tankless water heater from American rated 4.8 GPM at a 0.95 UEF.

Efficiency
Uniform Energy Factor (UEF)	0.95
Annual gas use (natural gas)	178 therms/yr
Recovery efficiency	98 %
Annual propane use	194.53 gal/yr

General
Fuel	Natural Gas, Propane

Capacity
Max flow rate	4.8 GPM
Draw pattern	High
Minimum activation flow	1 GPM

Performance
Gas input rate	160 kBTU/h

Installation
Max current draw	5 A
Vent type	Power Vent, Power Direct Vent
Vent size	3 / 2

Smart features
Smart / connected capable	No

Dimensions
Width	17 in
Depth	16 in

Certification
ENERGY STAR certified	Yes

Real flow rate by climate

A tankless heater's usable flow depends on how far it must raise incoming water temperature. Sustained hot-water flow of the American ATHR-160M 1 (MTHR-160X3 1) at common temperature rises (a typical shower uses about 2 GPM of mixed water):

Temperature rise	Climate	Sustained flow	Simultaneous showers
45 °F	Warm climate (~75 °F groundwater)	4.8 GPM	2
55 °F	Mild climate (~65 °F groundwater)	4.8 GPM	2
70 °F	Cold climate (~50 °F groundwater)	4.3 GPM	2
77 °F	DOE test condition	3.9 GPM	1

Compare the American ATHR-160M 1 (MTHR-160X3 1)

Similar water heaters

A. O. Smith ATHR-160M 1 (UEF 0.95)
A. O. Smith ATHR-160M 1 (ATHR-160X3 1) (UEF 0.95)
A. O. Smith ATHR-160M 1 (GT15THR-160M 1) (UEF 0.95)
A. O. Smith ATHR-160M 1 (GT15THR-160X3 1) (UEF 0.95)
A. O. Smith ATM-160M-N 1 (UEF 0.95)
A. O. Smith ATM-160M-N 1 (ATM-160X3-N 1) (UEF 0.95)

Frequently asked questions

Is the American ATHR-160M 1 (MTHR-160X3 1) ENERGY STAR certified?

Yes, the American ATHR-160M 1 (MTHR-160X3 1) holds a current ENERGY STAR certification for water heating efficiency (UEF 0.95).

How much does the American ATHR-160M 1 (MTHR-160X3 1) cost to run per year?

About $258 per year at national average energy rates, based on its certified annual energy use under the DOE test draw pattern. Your rate and usage change this figure.

What venting does the American ATHR-160M 1 (MTHR-160X3 1) use?

The American ATHR-160M 1 (MTHR-160X3 1) uses Power Vent, Power Direct Vent venting with 3 / 2 in vent connections. Matching the existing vent type is usually the cheapest replacement path.

Is the American ATHR-160M 1 (MTHR-160X3 1) a smart water heater?

No, the American ATHR-160M 1 (MTHR-160X3 1) is not connected-capable — it has no app connectivity or demand-response support.

Sources

data.energystar.gov (retrieved 2026-07-17)