WattCost

Data through April 2026

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

Rinnai REHP50CW

Heating a typical household's hot water, the Rinnai REHP50CW is certified at 861 kWh a year — about $162 at the U.S. average electricity rate, or $13.51 a month. That's 20% less than the median certified electric water heater, placing it comfortably in the efficient third of the field (108 of 566). Where you live moves the bill from $106 a year in North Dakota to $401 in Hawaii.

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

$162/yr

$121 · cheapest certified water heaters (electric)$328 · priciest
Per month
$13.51
Per day
44¢
Certified use
861 kWh/yr
Type
Hybrid/Electric Heat Pump
Heat pump type
240 Volt Integrated HPWH
Storage volume
46 gal
First-hour rating
71 gal
UEF
3.75
643 kWh1,741 kWh
Where the Rinnai REHP50CW (▮) sits among all 566 certified water heaters (electric), by annual kWh

What it costs in every state

Rinnai REHP50CW: 861 kWh/yr × each state's average residential rate (EIA)
StateRate ¢/kWhThis model $/yrRelative cost
Alabama17.4¢$150
Alaska27.4¢$235
Arizona15.5¢$133
Arkansas14.2¢$122
California35.3¢$304
Colorado16.5¢$142
Connecticut32.2¢$278
Delaware18.8¢$162
District of Columbia25.4¢$219
Florida15.4¢$132
Georgia15.4¢$132
Hawaiipriciest46.6¢$401
Idaho12.7¢$109
Illinois20.5¢$176
Indiana17.9¢$154
Iowa13.9¢$119
Kansas15.8¢$136
Kentucky15.0¢$129
Louisiana14.4¢$124
Maine28.4¢$245
Maryland22.1¢$190
Massachusetts29.4¢$254
Michigan21.4¢$184
Minnesota16.4¢$141
Mississippi16.8¢$144
Missouri14.0¢$121
Montana13.9¢$120
Nebraska13.3¢$114
Nevada14.3¢$123
New Hampshire27.2¢$235
New Jersey23.5¢$203
New Mexico15.2¢$130
New York29.4¢$254
North Carolina16.3¢$140
North Dakotacheapest12.3¢$106
Ohio19.5¢$168
Oklahoma13.3¢$115
Oregon15.8¢$136
Pennsylvania21.5¢$185
Rhode Island28.3¢$244
South Carolina17.1¢$147
South Dakota14.5¢$125
Tennessee14.9¢$129
Texas17.0¢$146
Utah13.3¢$114
Vermont24.6¢$211
Virginia17.4¢$150
Washington14.4¢$124
West Virginia16.1¢$138
Wisconsin19.2¢$165
Wyoming14.7¢$126

Certified models closest in efficiency

electric water heaters within reach of 861 kWh/yr
ModelkWh/yr$/yr (US avg)
Midea CAN3-RSJ-15/190RDVN3-L4861$162
Midea US3-RSJ-15/190RDVN3-L4861$162
Rinnai REHP50W861$162
Friedrich PROH40 T2 FD400-30859$162
Friedrich PROH40 T2 FD400-SO859$162
Rheem PROPH40 T2 RH375-30859$162

Run your own numbers

Your rate, your numbers

Per day
44¢
Per month
$13.51
Per year
$162

861 kWh/yr × 18.8¢/kWh = $162/yr

Prefilled with this model's certified 861 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 Rinnai REHP50CW use?
ENERGY STAR certifies the Rinnai REHP50CW at 861 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 Rinnai REHP50CW cost to run per month?
About $13.51 a month at the U.S. average residential rate (18.8¢/kWh) — 44¢ a day, or $162 a year. Your state's rate moves this up or down; see the table above.
Is the Rinnai REHP50CW energy efficient?
It uses 20% less electricity than the median certified electric water heater, placing it in the efficient third of certified models.
What does the Rinnai REHP50CW cost to run in the cheapest vs. priciest state?
At current residential rates it costs about $106 a year in North Dakota (12.3¢/kWh) and $401 in Hawaii (46.6¢/kWh).

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