ARISTON ENS40L-* vs Richmond PROPH40 T0 RH120-M: which uses less energy?
At the low draw pattern the Richmond PROPH40 T0 RH120-M uses 802 kWh a year and the ARISTON ENS40L-* 2,439 — 1,638 kWh (67%) less, about 16,379 kWh over ten years. Both are filed as an electric tank, 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 tank at the low draw pattern.
| Figure | ARISTON ENS40L-* | Richmond PROPH40 T0 RH120-M |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.92 | 2.8 (better) |
| Energy use per year (kWh) | 2,439 | 802 (better) |
| First hour rating (gal) | 46 | 45 |
| Rated storage volume (gal) | 36 | 36 |
| Installed cost range | $1,591–$1,802 | not published |
| ENERGY STAR certified | not matched | yes |
| Refrigerant | not filed | R-134a, GWP 1430 |
| On the market since | not filed | 2022-04-21 |
What it costs to run
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 Richmond PROPH40 T0 RH120-M if running cost matters most: it uses 1,638 kWh less a year on the same test.
- Pick the ARISTON ENS40L-* if you need more hot water in your busiest hour: it lists a first hour rating of 46 gallons against 45.
- Neither if your household's busiest hour needs more than 46 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.
Each model on its own
-
ARISTON ENS40L-*
Its filed figures, class position and running cost on your ZIP.
-
Richmond PROPH40 T0 RH120-M
Its filed figures, class position and running cost on your ZIP.