Stiebel Eltron Mini 3.5-1
0.93 UEF DOE CCD · 2026-09-19Grade F: 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 Stiebel Eltron Mini 3.5-1, an electric tankless unit, it uses 635 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 20 kWh above its class median of 615 kWh.
Energy use per year
635 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 above the median of 615 kWh for the 271 models registered in the same heater type and draw pattern; it ranks 218 of 271, lowest energy first.
Solid line: this model (635 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
- 0.93 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
$1,297–$1,766 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 Stiebel Eltron model on file
What this brand files, by heater type.
UEF 0.93 · Grade F Price it on your ZIP
This site computes the 635 kWh figure; the registry does not list it. The calculation uses the registry's UEF, the ratio of hot water delivered to energy used, and the DOE test's daily hot-water draw for the very small draw pattern. This model's UEF is 0.93, from DOE CCD data retrieved on 2026-09-19. The model is compared with the 271 models registered as an electric tankless unit at the very small draw pattern. In that group it ranks 218th of 271 for lowest energy use. That puts it in the highest quarter of its class for energy use. The class median is 615 kWh a year under the same test condition. The page on how the annual cost is calculated sets out each step of this method.
The very small draw pattern covers small units, such as a heater for a single bathroom or a point-of-use heater under a sink. The registry lists this model's maximum flow rate in gallons per minute as 0.4. A single tap that draws no more than 0.4 gallons per minute is within that listed maximum. Any demand above 0.4 gallons per minute is beyond what the registry lists for this model. Energy use at a daily draw other than the federal test's is not available in this data. If your need falls outside this draw pattern, the selector by fuel, space and size covers other classes. You can also find a same-class replacement by model number to compare other units at the very small draw pattern.
The text on this page does not state a running cost. The cost of 635 kWh of electricity a year depends on your own utility's electricity tariff. The cost calculator on your own ZIP works it out from your rate. The same rate also applies to the class median of 615 kWh a year. At that rate, the cost gap between this model and a median unit in its class is the price of 20 kWh of electricity a year. Both figures assume the very small draw pattern at the federal test's daily draw. The installed price range is shown in a separate block, with its source and date. It is a modeled installed-cost range, not a quote. Running cost at any other daily draw is not known from this data.
DOE CCD · 2026-09-19