DoesTheMath

EEMAX SPEX2412T vs Stiebel Eltron Mini-E 2.5-1: which uses less energy?

At the very small draw pattern the Stiebel Eltron Mini-E 2.5-1 uses 609 kWh a year and the EEMAX SPEX2412T 615 — 6 kWh (1%) less, about 63 kWh over ten years. Both are filed as an electric tankless unit, so the comparison holds. Enter your ZIP below to price the difference.


Side by side

Compared within one class only: models filed as an electric tankless unit at the very small draw pattern.

Filed and computed figures
Figure EEMAX SPEX2412T Stiebel Eltron Mini-E 2.5-1
UEF (Uniform Energy Factor) 0.96 0.97 (better)
Energy use per year (kWh) 615 609 (better)
Max flow (GPM) 0.2 0.2
Installed cost range $1,306–$1,838 $1,309–$1,862
ENERGY STAR certified not matched not matched
DOE CCD · 2026-09-19

What it costs to run

EEMAX SPEX2412T: 615 kWh a year Stiebel Eltron Mini-E 2.5-1: 609 kWh a year

EEMAX SPEX2412T — 615 kWh a year Stiebel Eltron Mini-E 2.5-1 — 609 kWh a year

Stiebel Eltron Mini-E 2.5-1 is 6 kWh a year lower than EEMAX SPEX2412T.

DOE CCD · 2026-09-19

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Reliability

Not published: Reliability, failure rates and each model’s actual warranty term.

The registries these figures come from certify energy performance under a federal test; none of them records how long a unit lasts or how often it fails, so this page does not rank the two on reliability.

What is here instead:

  • The filed efficiency, capacity and tank size of both models, side by side below.
  • The actual warranty term is printed in each model’s documentation, not in any registry.

Which should you pick?

  • Pick the Stiebel Eltron Mini-E 2.5-1 if running cost matters most: it uses 6 kWh less a year on the same test.
  • Pick the EEMAX SPEX2412T if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the Stiebel Eltron Mini-E 2.5-1.
  • Neither if you need more than 0.2 GPM at the same time — neither unit lists more. Check how to size a tankless unit by GPM.

Each model on its own