RELIANCE WATER HEATERS ATM-140M-N 1**
0.95 UEF DOE CCD · 2026-09-19Grade B: where this UEF sits among the 397 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set
A gas tankless unit, high draw pattern (a larger household, or one where showers and laundry overlap).
If you are checking the RELIANCE WATER HEATERS ATM-140M-N 1**, a gas tankless unit, it uses 178 therms of natural gas a year. That figure belongs to the high draw pattern, the standard daily hot-water usage DOE tests against. It sits 4 therms below its class median of 182 therms, ranking 45th lowest of 397 models.
Energy use per year
178 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 182 therms for the 397 models registered in the same heater type and draw pattern; it ranks 45 of 397, lowest energy first.
Solid line: this model (178 therms). Dashed line: the class median.
Min 173 therms Median 182 therms Max 209 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
- 0.95 DOE CCD · 2026-09-19 Compared only with other models registered as a gas tankless unit at the high draw pattern.
- Draw Pattern the standard daily usage profile DOE tests the unit against
- High DOE CCD · 2026-09-19
- Maximum Gallons Per Minute how many gallons a minute it can heat while running continuously
- 4.1 gal/min DOE CCD · 2026-09-19
- On the market since (ENERGY STAR) the date the manufacturer told ENERGY STAR the model went on sale
- 2026-08-28 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
$2,358–$3,405 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 · 2026-09-24Does 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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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 0.95 · Grade B Price it on your ZIP
The 178 therms figure is not printed in the registry. This site computed it from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.95 for this model. The second input is the DOE test's daily hot-water draw for the high draw pattern. The registry values were retrieved from the DOE CCD on 2026-09-19. The figure therefore holds at the federal test's draw, not at your household's actual use. A home that draws more hot water each day than the test assumes will use more gas than 178 therms. A home that draws less will use less. How much more or less is not available from the registry data. The full calculation is set out in how this site calculates annual energy and running cost.
The high draw pattern describes a larger household, or one where showers and laundry overlap. This model's rated maximum flow rate in gallons per minute is 4.1. A household that needs more than 4.1 gallons per minute at the same moment falls outside that rating. Within its class of 397 gas tankless units tested at the high draw pattern, it ranks 45th lowest for energy use. That places it in the lowest quarter of the class. The gap to the class median of 182 therms is 4 therms a year, both at the test's draw. The ranking compares energy use only and says nothing about flow, price or service life. To match a unit in the same class, the same-class replacement search by model number lists the other registered models.
The running cost is not given in this text. It depends on your state's average residential gas price, so the page computes it from your ZIP. The same 178 therms a year produces a different cost in each state. The 4 therms gap to the class median also changes in cost with that price. To see the figure at your own rate, use the running-cost calculator for your ZIP. The installed price range shown elsewhere on this page is a modeled range with its own source and date, not a quote. The running cost in a home whose daily draw differs from the test is not available here.
DOE CCD · 2026-09-19