MRCOOL MTWH04550ET
0.92 UEF DOE CCD · 2026-09-19Grade G: where this UEF sits among the 426 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set
An electric tank, medium draw pattern (a typical three- or four-person household, about 55 gallons on a busy morning).
Checking the MRCOOL MTWH04550ET? This electric tank uses 3,531 kWh of electricity a year at the medium draw pattern, the standard daily hot-water usage DOE tests against. That figure equals its class median of 3,531 kWh, a difference of 0 kWh. It ranks 213th lowest in energy use of the 426 comparable models.
Energy use per year
3,531 kWh a year
Computed by this site from the registry's UEF and the federal test's daily hot-water draw for this draw pattern. What it costs depends on the electricity rate where you live.
That is equal to the median of 3,531 kWh for the 426 models registered in the same heater type and draw pattern; it ranks 213 of 426, lowest energy first.
Solid line: this model (3,531 kWh). Dashed line: the class median.
Min 773 kWh Median 3,531 kWh Max 3,569 kWh
What it costs to run where you live
What the registry files
- UEF (Uniform Energy Factor) how much hot water you get for each unit of energy the heater uses
- 0.92 DOE CCD · 2026-09-19 Compared only with other models registered as an electric tank at the medium draw pattern.
- Draw Pattern the standard daily usage profile DOE tests the unit against
- Medium DOE CCD · 2026-09-19
- First Hour Rating how many gallons of hot water the unit can deliver in one hour, starting from a full tank
- 63 gal DOE CCD · 2026-09-19
- Rated Storage Volume the tank size in gallons
- 45 gal DOE CCD · 2026-09-19
What it costs to install
$1,721–$2,028 installed
Not a quote — a modeled range of what installers have charged for this class of unit; your price will vary with labor rates, access, and local code requirements.
Escalation indexes: equipment (BLS PPI) latest available: August 2026; labor (BLS ECI) latest available: April 2026 to June 2026.
NLR REMDB (BLS PPI/ECI escalated) · 2026-04-01Safety record
No CPSC recall names this model.
Checked against the CPSC recall database. CPSC does not publish a model-level match for this product category, so this list is curated by hand from the manufacturer's recall filings.
CPSC · 2026-09-24What these figures mean
How this compares
The closest models in the same class — same fuel, type and draw pattern.
Keep going
How every figure on this page is calculated
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Find what replaces your water heater
Enter the model number off your old unit and see what is on file today, with the yearly cost difference.
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Find a water heater that fits
Three questions — fuel, hot water need, install space — narrow every model on file to the ones that fit.
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What a water heater costs to run
Prices a unit's efficiency against your own utility's filed tariff for your ZIP code.
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Is a 40-gallon water heater enough?
Answered from what models in this size actually file.
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Water heaters
Every model on file with the Department of Energy, by heater type.
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All electric resistance tank water heaters
Electric tanks that file a UEF below 2.0 — heated by elements, not a heat pump.
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Every MRCOOL model on file
What this brand files, by heater type.
UEF 0.92 · Grade G Price it on your ZIP
The 3,531 kWh figure comes from this site's own calculation, not from the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the daily hot-water draw in the DOE test for the medium draw pattern. For this model the UEF is 0.92, from DOE CCD data retrieved 2026-09-19. The figure therefore holds only at the federal test's daily draw. A household that draws more or less hot water than the test assumes will use a different amount. This page does not know that amount. The steps behind the calculation are set out in how the annual cost is calculated.
The MRCOOL MTWH04550ET has a rated volume of 45 gallons. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 63 gallons. The annual figure applies to a household whose daily hot-water use is close to the medium draw pattern. For a household well above or below that draw, the annual figure will differ, as the paragraph above explains. A reader who needs lower energy use in the same class should look for a model below the class median of 3,531 kWh. To start from this unit's class, use the search for a same-class replacement by model number. The selector by fuel, space and size covers other heater types.
This text does not state the running cost. It depends on your own utility's electricity tariff, which this page does not know. The cost calculator on your own ZIP applies your local rate to the 3,531 kWh described above. The result keeps the same condition: it holds at the medium draw pattern and the federal test's daily draw. If your household draws more hot water than the test assumes, your cost will be higher. If it draws less, your cost will be lower. The installed price appears in its own block on this page as a modeled range with its own source and date. It is not a quote, and it is separate from the yearly running cost.
DOE CCD · 2026-09-19