NAVIEN NHW700-199AI-NG
0.81 UEF DOE CCD · 2026-09-19Grade G: 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 NAVIEN NHW700-199AI-NG, this gas tankless unit uses 209 therms of natural gas a year at the high draw pattern. The draw pattern is the standard daily hot-water usage DOE tests against. That figure sits 27 therms above the 182 therms median of the 397 models in its class.
Energy use per year
209 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 182 therms for the 397 models registered in the same heater type and draw pattern; it ranks 323 of 397, lowest energy first.
Solid line: this model (209 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
- 0.81 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
- 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
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 NAVIEN model on file
What this brand files, by heater type.
UEF 0.81 · Grade G Price it on your ZIP
The registry does not print the 209 therms figure. This site computed it from the registry's UEF, the ratio of hot water delivered to energy used, and from the DOE test's daily hot-water draw for the high pattern. The UEF for this model is 0.81. The annual figure therefore holds only at that federal test draw. A home that draws more or less hot water will use a different amount of gas. The comparison class is the 397 models registered as gas tankless units at the high draw pattern. In that class, this unit ranks 323rd for lowest energy use, which places it in the highest quarter for energy use. The source is DOE CCD, retrieved 2026-09-19. The inputs are set out on the page explaining how the annual cost is calculated.
The high draw pattern describes a larger household, or one where showers and laundry overlap. The 209 therms figure applies to a home that matches that description. For such a home, the figure can be compared directly with the 182 therms class median. For a household that uses less hot water, the figure does not describe its likely use, because it belongs to the high test draw. The registry lists a maximum flow rate in gallons per minute of 5 for this unit. How many fixtures that rate covers at once in a given home is not available in this data. If you are verifying a unit already in place, you can find a same-class replacement by model number and compare its energy use with this model's 209 therms.
The running cost is not stated in this text. It depends on your state's average residential gas price, so the page computes it from your ZIP. The same rate applies to the 27 therms gap between this model and the class median. What that gap costs each year therefore also depends on the state, and it is not given here. To see the running cost for 209 therms of natural gas at your rate, enter your ZIP in the cost calculator for your own ZIP. The installed price range appears in its own block on this page, with its source and date. It is a modeled installed-cost range, not a quote.
DOE CCD · 2026-09-19