A. O. Smith GCB-40 4** vs Reliance GCR-40 410: which uses less energy?
An asterisk in a model number stands for any character: one filing covers several variants.
At the high draw pattern the A. O. Smith GCB-40 4** and the Reliance GCR-40 410 use the same energy, 264 therms a year each, on the same federal test. Both are filed as a gas tank, so the comparison holds; what separates them is below. Enter your ZIP to price either one on your own rate.
Side by side
Compared within one class only: models filed as a gas tank at the high draw pattern.
| Figure | A. O. Smith GCB-40 4** | Reliance GCR-40 410 |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.64 | 0.64 |
| Energy use per year (therms) | 264 | 264 |
| First hour rating (gal) | 78 | 80 |
| Rated storage volume (gal) | 38 | 38 |
| Installed cost range NLR REMDB | $1,643–$2,763 | $1,643–$2,763 |
| CPSC recall naming it CPSC | none on file | none on file |
DOE CCD · 2026-09-19 NLR REMDB · 2026-04-01 CPSC · 2026-09-24
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 above.
- No CPSC recall on file names either model (list checked 2026-09-24).
- The actual warranty term is printed in each model’s documentation, not in any registry.
Which should you pick?
- Pick the Reliance GCR-40 410 if you need more hot water in your busiest hour: it lists a first hour rating of 80 gallons against 78.
- Neither if your household's busiest hour needs more than 80 gallons of hot water — neither lists more. Check whether a 40-gallon heater is enough.
Each model on its own
- A. O. Smith GCB-40 4** 264 therms a year
- Reliance GCR-40 410 264 therms a year