RELIANCE WATER HEATERS GUC-30 4**
0.59 UEF DOE CCD · 2026-09-19Grade G: where this UEF sits among the 288 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set
A gas tank, medium draw pattern (a typical three- or four-person household, about 55 gallons on a busy morning).
Checking this model: it uses 188 therms of natural gas a year at the medium draw pattern, the standard daily hot-water usage DOE tests against. That is 3 therms above the class median of 185 therms among the 288 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 above the median of 185 therms for the 288 models registered in the same heater type and draw pattern; it ranks 186 of 288, lowest energy first.
Solid line: this model (188 therms). Dashed line: the class median.
Min 148 therms Median 185 therms Max 194 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
- 0.59 DOE CCD · 2026-09-19 Compared only with other models registered as a gas tank at the medium draw pattern.
- Draw Pattern the standard daily usage profile DOE tests the unit against
- Medium 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
- 62 gal DOE CCD · 2026-09-19
- Rated Storage Volume the tank size in gallons
- 29 gal DOE CCD · 2026-09-19
What it costs to install
Not published: Installed cost range
This model's rated tank size 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 · 2026-09-24What 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 30-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 0.59 · Grade G Price it on your ZIP
The registry lists a UEF, the ratio of hot water delivered to energy used, of 0.59 for this model. The registry does not publish an annual energy figure. This site computed 188 therms from that UEF and the daily hot-water draw in the DOE test for the medium draw pattern, so the figure applies only under that condition. The source is DOE CCD, retrieved 2026-09-19. Among the 288 gas tank models at that draw pattern, this model ranks 186th lowest for energy use, which places it in the second-highest quarter of its class. The steps behind the calculation are set out in how the annual cost is calculated.
The class median is 185 therms, and this model sits 3 therms above it at the medium draw pattern. Under the same test conditions it therefore uses more gas than the median model of its class. The figure fits a household whose hot-water use resembles the medium draw pattern. It says little about a household with much larger or smaller use, because energy depends on the amount of water heated. The first hour rating, the gallons of hot water available in the first hour from a full tank, is 62 gallons, and the rated volume is 29 gallons. A household that needs more than 62 gallons in one hour is outside what this rating shows. The selector by fuel, space and size can be used to compare other models.
The running cost is not stated here, because it depends on the state average residential gas price, which differs by reader. Multiplying 188 therms by your own gas price gives a yearly cost for the medium draw pattern. The cost calculator on your own ZIP does this with the state average. The result changes if your household's draw differs from the medium draw pattern. An installed price range is not published for this model, because its ratings lie outside the range the cost database's model was fitted on, and the range is not stretched past it. This entry is RELIANCE WATER HEATERS, model GUC-30 4**, a gas tank heater.
DOE CCD · 2026-09-19