Rheem SPEX48T
0.97 UEF DOE CCD · 2026-09-19Grade E: where this UEF sits among the 271 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set
An electric tankless unit, very small draw pattern (small units - a single bathroom, or a point-of-use heater under a sink).
If you are checking the Rheem SPEX48T, it uses 609 kWh of electricity a year at the federal test's daily hot-water draw. That figure belongs to the very small draw pattern, the standard daily hot-water usage DOE tests against. It sits 6 kWh below its class median of 615 kWh, ranking 37th lowest of 271.
Energy use per year
609 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 below the median of 615 kWh for the 271 models registered in the same heater type and draw pattern; it ranks 37 of 271, lowest energy first.
Solid line: this model (609 kWh). Dashed line: the class median.
Min 562 kWh Median 615 kWh Max 649 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
- 0.97 DOE CCD · 2026-09-19 Compared only with other models registered as an electric tankless unit at the very small draw pattern.
- Draw Pattern the standard daily usage profile DOE tests the unit against
- Very small DOE CCD · 2026-09-19
- Maximum Gallons Per Minute how many gallons a minute it can heat while running continuously
- 0.4 gal/min DOE CCD · 2026-09-19
What it costs to install
$1,309–$1,862 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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How to size a tankless water heater by GPM
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 tankless water heaters
Electric instantaneous units, sized by flow rate rather than tank gallons.
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Every Rheem model on file
What this brand files, by heater type.
UEF 0.97 · Grade E Price it on your ZIP
This site calculated the 609 kWh figure. The registry does not publish it. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the DOE test's daily hot-water draw for this draw pattern. For the SPEX48T, the UEF is 0.97. The registry values come from the DOE CCD, retrieved 2026-09-19. The class behind the ranking is the 271 models registered as an electric tankless unit at the very small draw pattern. Within that class, the unit sits 6 kWh below the 615 kWh median and ranks 37th lowest. That puts it in the lowest quarter of its class for energy use. The figure holds only at the test's daily draw. This unit's energy use in a particular home is not available here. The steps are explained in how the annual cost is calculated.
The very small draw pattern covers small units: a single bathroom, or a point-of-use heater under a sink. The SPEX48T is rated at a maximum flow rate in gallons per minute of 0.4. That rating and the 609 kWh test figure both describe this narrow use. A plumber or seller confirming a point-of-use fit can check the unit against that 0.4 limit. Demand above 0.4 at once is beyond the rated flow, so the rating does not describe whole-house use. If a home needs a larger draw pattern, the class comparison on this page does not apply, because it covers only very small units. To compare other classes, use the selector by fuel, space and size, or find a same-class replacement by model number.
The text on this page does not state a running cost. The cost of 609 kWh of electricity depends on your own utility electricity tariff, so the page works it out from your ZIP. The cost calculator on your own ZIP applies that tariff to the same test-draw figure. The unit sits 6 kWh below its class median. At the same tariff, its running cost differs from a median unit's by the cost of 6 kWh. The installed price range appears in its own block with its source and date. It is a modeled installed-cost range, not a quote. The running cost in a home that draws more or less hot water than the test is unknown.
DOE CCD · 2026-09-19