Ruud 88H40*
Ruud 88H40* is in the DOE listing as of Oct 19, 2026.
- Tabletop water heater
- 1 listed model
ENERGY STAR certification does not cover this type of water heater.
Its figures are also listed under Rheem 88H40*.
Certified figures
- Storage volume
- 36gallons
- UEF
- 0.81Uniform energy factor
- First-hour rating
- 50gallonsHot water in the first hour
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| Model number | Storage volume (gal) | UEF | First-hour rating (gal) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|---|
| PET40* | 36 | 0.81 | 50 | 98% | Low |
UEF is the uniform energy factor. A dash means the model has no such figure.
It holds 36 gallons in the test, 4 gallons less than its 40-gallon sold size. Starting full, it gives 50 gallons of hot water in its first hour of use. Its tank holds 36 gallons, so reheating adds 14 gallons during the first hour. In the first hour, 4 of the 7 tabletop models give more hot water. The median tabletop model gives 55 gallons in its first hour.
In tests, 81% of the energy went to hot water, so its UEF is 0.81. Its test ran at the low level of daily hot water use. Of 3 tabletop models with the same draw pattern, none has a higher UEF. On its draw pattern, its UEF is also the median tabletop UEF. Of the energy spent to reheat water, 98% goes into it (its recovery efficiency).
There are 2 more basic models with the same test figures. Of those, one or more are under the Rheem and Richmond brands. You can find the whole group on the page for the Rheem 88H40*.
Also listed as
They carry every figure in the table above.
- Every Ruud basic model
- Every 40-gallon electric storage water heater
- Every electric storage water heater
Not covered
- Advertised figures. We have none on file for this model.