WattCost

Data through April 2026

Running cost · Water Heaters (Electric) · ENERGY STAR certified

A. O. Smith HPACO-45C 1**+AXST-66C 1

For a standard household draw pattern, the A. O. Smith HPACO-45C 1**+AXST-66C 1 uses a certified 1,341 kWh per year: roughly $253 annually at the national average rate. It sits near the bottom of the certified table — using 24% more than the median electric water heater (rank 467 of 566) — so the state you live in matters more than usual. Where you live moves the bill from $166 a year in North Dakota to $625 in Hawaii.

Estimated annual running cost · U.S. average rate 18.8¢/kWh

$253/yr

$121 · cheapest certified water heaters (electric)$328 · priciest
Per month
$21.04
Per day
69¢
Certified use
1,341 kWh/yr
Type
Hybrid/Electric Heat Pump
Heat pump type
Split System HPWH
Storage volume
60 gal
First-hour rating
82 gal
UEF
3.7
643 kWh1,741 kWh
Where the A. O. Smith HPACO-45C 1**+AXST-66C 1 (▮) sits among all 566 certified water heaters (electric), by annual kWh

What it costs in every state

A. O. Smith HPACO-45C 1**+AXST-66C 1: 1,341 kWh/yr × each state's average residential rate (EIA)
StateRate ¢/kWhThis model $/yrRelative cost
Alabama17.4¢$233
Alaska27.4¢$367
Arizona15.5¢$208
Arkansas14.2¢$190
California35.3¢$473
Colorado16.5¢$222
Connecticut32.2¢$432
Delaware18.8¢$252
District of Columbia25.4¢$341
Florida15.4¢$206
Georgia15.4¢$206
Hawaiipriciest46.6¢$625
Idaho12.7¢$170
Illinois20.5¢$275
Indiana17.9¢$240
Iowa13.9¢$186
Kansas15.8¢$212
Kentucky15.0¢$201
Louisiana14.4¢$194
Maine28.4¢$381
Maryland22.1¢$296
Massachusetts29.4¢$395
Michigan21.4¢$287
Minnesota16.4¢$220
Mississippi16.8¢$225
Missouri14.0¢$188
Montana13.9¢$186
Nebraska13.3¢$178
Nevada14.3¢$192
New Hampshire27.2¢$365
New Jersey23.5¢$316
New Mexico15.2¢$203
New York29.4¢$395
North Carolina16.3¢$218
North Dakotacheapest12.3¢$166
Ohio19.5¢$261
Oklahoma13.3¢$178
Oregon15.8¢$212
Pennsylvania21.5¢$288
Rhode Island28.3¢$380
South Carolina17.1¢$229
South Dakota14.5¢$195
Tennessee14.9¢$200
Texas17.0¢$228
Utah13.3¢$178
Vermont24.6¢$329
Virginia17.4¢$233
Washington14.4¢$193
West Virginia16.1¢$215
Wisconsin19.2¢$258
Wyoming14.7¢$197

Certified models closest in efficiency

electric water heaters within reach of 1,341 kWh/yr
ModelkWh/yr$/yr (US avg)
A. O. Smith HPACO-45 1**+AXST-66 11,341$253
A. O. Smith HPACO-45 1**+AXST-66TTP 11,341$253
A. O. Smith HPACO-45C 1**+AXST-66CTTP 11,341$253
American MHPCO-45 1**+MXST-66 11,341$253
American MHPCO-45 1**+MXST-66TTP 11,341$253
Giant GTHPCO-45 1**+GTXST-66 11,341$253

Run your own numbers

Your rate, your numbers

Per day
69¢
Per month
$21.04
Per year
$253

1,341 kWh/yr × 18.8¢/kWh = $253/yr

Prefilled with this model's certified 1,341 kWh/yr — adjust if your usage differs from the DOE test basis. The certified annual kWh comes from the DOE Uniform Energy Factor test, which simulates a typical household's daily hot-water draw pattern. Only electric models (including heat-pump units) are listed — gas models burn gas, not kWh.

Questions, answered with the data

How much electricity does the A. O. Smith HPACO-45C 1**+AXST-66C 1 use?
ENERGY STAR certifies the A. O. Smith HPACO-45C 1**+AXST-66C 1 at 1,341 kWh per year. The certified annual kWh comes from the DOE Uniform Energy Factor test, which simulates a typical household's daily hot-water draw pattern. Only electric models (including heat-pump units) are listed — gas models burn gas, not kWh.
How much does the A. O. Smith HPACO-45C 1**+AXST-66C 1 cost to run per month?
About $21.04 a month at the U.S. average residential rate (18.8¢/kWh) — 69¢ a day, or $253 a year. Your state's rate moves this up or down; see the table above.
Is the A. O. Smith HPACO-45C 1**+AXST-66C 1 energy efficient?
It uses 24% more electricity than the median certified electric water heater, which puts it among the least efficient certified models.
What does the A. O. Smith HPACO-45C 1**+AXST-66C 1 cost to run in the cheapest vs. priciest state?
At current residential rates it costs about $166 a year in North Dakota (12.3¢/kWh) and $625 in Hawaii (46.6¢/kWh).

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