RELIANCE WATER HEATERS TK-110U-E 2**
0.81 UEF DOE CCD · 2026-09-19Grade G: where this UEF sits among the 80 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set
A gas tankless unit, medium draw pattern (a typical three- or four-person household, about 55 gallons on a busy morning).
For a registry check: RELIANCE WATER HEATERS TK-110U-E 2** uses 137 therms of natural gas a year at the medium draw pattern, the standard daily hot-water usage DOE tests against. That is 2 therms above the class median of 135 therms, and ranks 52nd lowest of 80 models.
Energy use per year
137 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 135 therms for the 80 models registered in the same heater type and draw pattern; it ranks 52 of 80, lowest energy first.
Solid line: this model (137 therms). Dashed line: the class median.
Min 114 therms Median 135 therms Max 137 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
- 0.81 DOE CCD · 2026-09-19 Compared only with other models registered as a gas tankless unit at the medium draw pattern.
- Draw Pattern the standard daily usage profile DOE tests the unit against
- Medium DOE CCD · 2026-09-19
- Maximum Gallons Per Minute how many gallons a minute it can heat while running continuously
- 3.5 gal/min DOE CCD · 2026-09-19
What it costs to install
$1,698–$2,632 installed
Not a quote — a modeled range of what installers have charged for this class of unit; your price will vary with labor rates, access, and local code requirements.
Escalation indexes: equipment (BLS PPI) latest available: August 2026; labor (BLS ECI) latest available: April 2026 to June 2026.
NLR REMDB (BLS PPI/ECI escalated) · 2026-04-01Safety 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
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Find a water heater that fits
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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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How to size a tankless water heater by GPM
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 tankless water heaters
Gas-fired instantaneous units, sized by flow rate rather than tank gallons.
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Every RELIANCE WATER HEATERS model on file
What this brand files, by heater type.
UEF 0.81 · Grade G Price it on your ZIP
The figure of 137 therms for RELIANCE WATER HEATERS TK-110U-E 2** is computed by this site, not by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the DOE test's daily hot-water draw for the medium draw pattern. The UEF listed for this model is 0.81. The source is DOE CCD, retrieved 2026-09-19. The value applies to natural gas at that draw only. A household that draws more or less hot water than the test assumes will use a different amount, and this page has no figure for those cases. Against the class median of 135 therms, the model's figure is 2 therms higher, measured across 80 models registered as a gas tankless unit at the same draw pattern.
The model ranks 52nd lowest in energy use of 80, which places it in the second-highest quarter of its class for energy use. The models ranked ahead of it use less than 137 therms at the same draw pattern. The registry lists a maximum flow rate in gallons per minute of 3.5. The temperature rise that rating assumes is not available in this data. The figure suits a reader confirming a listing or a quote against registry data for a household close to the medium pattern. It suits a reader looking for the lowest gas use in the class less well. To compare options, use the selector by fuel, space and size or find a same-class replacement by model number.
The running cost is not stated in the text, because it depends on your state's average residential gas price. The calculation multiplies the model's 137 therms by that price, at the medium draw pattern. This text does not estimate a cost. The cost calculator on your own ZIP applies your state's price to the 137 therms figure. The method behind the annual cost lists the steps. The 2 therms gap to the class median of 135 therms converts to a yearly cost difference the same way, using your price. A different draw pattern or a different gas rate changes both results.
DOE CCD · 2026-09-19