Hot Water List

Giant UTM-199X3-P 1*1

Giant UTM-199X3-P 1*1 is in the ENERGY STAR list as of Oct 19, 2026.

  • Gas tankless water heater
  • 1 listed model

No certified figures were found under this model number. Units made for another brand are often certified under that brand's basic model.

Its figures are also listed under A. O. Smith ATM-199M-N 1**.

Certified figures

Flow at a 67°F rise
6.0gallons per minute
UEF
0.95Uniform energy factor

Flow where you live

A bigger rise from colder incoming water leaves the heater with 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 5.7 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.

Product history

Giant UTM-199X3-P 1*1 has a recorded ENERGY STAR market-availability date of May 15, 2026. It first appeared in the ENERGY STAR list between February 2026 and August 2026.

ENERGY STAR certified models

Giant UTM-199X3-P 1*1: ENERGY STAR certified models
Model numberUEFFlow at a 67°F rise (gal/min)Recovery efficiency
UTM-199X3-P 1*10.956.096%

It heats 6.0 gallons per minute of water by 67°F in the test. The median flow among gas tankless models is 4.8 gallons per minute. Of 487 gas tankless models, 4 have a higher flow than this one.

It is ENERGY STAR certified under its single model number. In tests, 95% of the energy it uses ends up as hot water (UEF 0.95). Its test ran at the high level of daily hot water use. Of 399 gas tankless models with the same draw pattern, 49 have a higher UEF. A UEF of 0.93 is the median for its type and draw pattern. While it heats water, 96% of the energy used goes into the water (its recovery efficiency).

All of its test figures are shared by 8 other basic models. Besides this brand, 6 brands list one or more of them. You can find the whole group on the page for the A. O. Smith ATM-199M-N 1**.

It may qualify for 6 rebate programs. Another 2 rebate programs may accept it if it meets their other terms.

Also listed as

They carry every figure in the table above.

Rebates

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

Updated Oct 19, 2026 · Methodology

Not covered

  • Advertised figures. We have none on file for this model.