RELIANCE WATER HEATERS GPCX-50L 1**
0.9 UEF DOE CCD · 2026-09-19Grade A: where this UEF sits among the 414 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set
A gas tank, high draw pattern (a larger household, or one where showers and laundry overlap).
If you are verifying the RELIANCE WATER HEATERS GPCX-50L 1**, a gas tank water heater, it uses 188 therms of natural gas a year. That figure applies at the high draw pattern, the standard daily hot-water usage DOE tests against. It is 72 therms below the 260 therms median of the 414 gas tank models registered at that draw pattern.
Energy use per year
188 therms 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 natural gas rate where you live.
That is below the median of 260 therms for the 414 models registered in the same heater type and draw pattern; it ranks 1 of 414, lowest energy first.
Solid line: this model (188 therms). Dashed line: the class median.
Min 188 therms Median 260 therms Max 277 therms
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
- 0.9 DOE CCD · 2026-09-19 Compared only with other models registered as a gas tank at the high draw pattern.
- Draw Pattern the standard daily usage profile DOE tests the unit against
- High DOE CCD · 2026-09-19
- First Hour Rating how many gallons of hot water the unit can deliver in one hour, starting from a full tank
- 118 gal DOE CCD · 2026-09-19
- Rated Storage Volume the tank size in gallons
- 49 gal DOE CCD · 2026-09-19
- On the market since (ENERGY STAR) the date the manufacturer told ENERGY STAR the model went on sale
- 2021-10-01 ENERGY STAR · 2026-09-19
- Connected / demand response (ENERGY STAR) whether the unit can take signals from your utility to shift when it heats, and by which standard (such as CTA-2045)
- No ENERGY STAR · 2026-09-19
What it costs to install
Not published: Installed cost range
This model's UEF lies outside the range NLR REMDB's cost model was fitted on, and the range is not stretched past it.
The annual energy figure on this page does not depend on this range and is unaffected.
Safety 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 · 2026-09-24Does it fit your space?
Enter your own numbers below — this compares them to what ENERGY STAR publishes for this model, it does not tell you what to buy.
- Dimensions (ENERGY STAR)
- the unit's filed height, width, depth or tank diameter, in inches
- Input voltage and maximum current (ENERGY STAR)
- the circuit voltage the unit is certified on and the most current it draws
- Vent type and size (ENERGY STAR)
- how a gas unit is vented, the vent's diameter and the height of its vent connector
What 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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Is a 50-gallon water heater enough?
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 gas tank water heaters
Gas-fired storage tanks, every size and draw pattern on file.
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Every RELIANCE WATER HEATERS model on file
What this brand files, by heater type.
UEF 0.9 · Grade A Price it on your ZIP
The 188 therms figure is computed by this site, not the registry. It combines two things: the registry's UEF, the ratio of hot water delivered to energy used, and the DOE test's daily hot-water draw for the high draw pattern. For this model the UEF is 0.9, and the source is the DOE CCD, retrieved 2026-09-19. The figure describes the federal test day, not a particular home. Energy use at a different daily draw is not available here. Within its class, the model ranks 1st lowest energy use of 414. That places it in the lowest quarter of its class for energy use. The steps behind the figure are set out in how the annual cost is calculated.
The high draw pattern stands for a larger household, or one where showers and laundry overlap. This unit has a rated volume of 49 gallons. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 118 gallons. A plumber or seller checking a match can compare those two ratings with the household's busiest hour of hot-water use. A home with lower demand is tested at a different draw pattern, so the class comparison on this page does not apply to it. This model's energy use at another draw pattern is not available here. To look up a registered model in the same class, use the same-class replacement finder by model number.
Running cost is not stated in this text. It depends on the state average residential gas price where the unit runs. The page therefore applies the reader's own rate, found from the ZIP, to the 188 therms figure. Enter a ZIP in the cost calculator on your own ZIP to see the result for your rate. The gap of 72 therms below the class median is in therms; its value in money is unknown until a rate is applied. An installed price range is not published for this model. Its ratings lie outside the range the cost database's model was fitted on, and the range is not stretched past it.
DOE CCD · 2026-09-19