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Gas water heaters are energy efficient

Gas water heaters are a popular choice thanks to their energy efficiency. In addition, in many parts of the country, gas is a relatively low cost fuel. Because of that, the experts at say gas models cost about half as much to run compared to conventional electric storage tank water heaters, although they do cost a bit more upfront. If you can install a gas line at a decent cost or already have natural gas service in your home, gas water heaters are easy to install and provide significant savings over time. Some gas-fired units can also run using propane; while fuel-cost savings might be less depending on the current cost of propane, it still will cost less in most cases than using electricity.

Gas hot water heaters work faster than electric models, which means you'll have more hot water available during peak usage. That also means that many households can get by with a smaller storage tank -- especially important in light of the 2015 NACEA regulations, which we discuss in detail in the introduction to this report.

If you have a family of five or so, we saw some great owner reviews for the Whirlpool 50T12-40DNG (Est. $800), a 50 gallon water heater with a tall profile. It is Energy Star Qualified, and with an ER of .67, easily meets all 2015 energy efficiency rules.

Feedback is excellent for the Whirlpool 50T12-40DNG. names the Whirlpool brand as the top choice among gas water heaters, and notes that those in its 6th Sense high-efficiency series, including the 50T12-40DNG, are the company's best products. "They feature electronic ignition controls as well as an automatic flue damper and they are backed by a very good warranty," says the site's Richard Reed.

The features on the Whirlpool 50T12-40DNG are ample. Those include a low NOx (nitrogen oxide) burner to reduce emissions by up to 33 percent. It's also certified to work at high altitudes of up to 10,100 feet above sea level. An LED display provides feedback on the gas water heater's status based on built-in self-diagnostics. The electronic ignition system shuts off the pilot when the heater is on standby, cutting gas consumption. The 50T12-40DNG has a tall profile (63.25 inches) meaning installation in a full basement or closet is required. The limited warranty covers parts for 12 years and labor for three years, which is better than what's found on many competing gas water heaters.

User feedback is on the Whirlpool 50T12-40DNG excellent. Though some are originally posted at the manufacturer's web site, you can find almost 290 user reviews at, the primary seller of the Whirlpool 50T12-40DNG, where it earns a rating of 4.6 stars. Around 98 percent give it their recommendation.

If your family is a little smaller, the Whirlpool 40T12-40DNG (Est. $700) is equally well liked. Its 40-gallon capacity is suitable for families of up to four people. Like the Whirlpool 50T12-40DNG, this water heater has an EF of .67 and is Energy Star Qualified. Its feature line up (save for capacity) and warranty are identical as well.

There are nearly 240 reviews of 40-gallon Whirlpool 40T12-40DNG gas water heater at Whirlpool's site, and some of those are also reflected in the nearly 40 reviews we saw at Regardless, satisfaction is high (4.5 stars at, 4.4stars at Roughly 97 percent of owners weighing in at recommend this 40-gallon hot water heater, while it gets a thumbs-up from 95 percent of customers.

If there's a drawback to these Whirlpool gas water heaters is that they are a little on the pricey side. If your budget is tighter, the Rheem XG40T09HE40U0 Performance Plus (Est. $470) 40-gallon water heater is worth a look. It's not as energy efficient as the Whirlpool models above, and is not Energy Star Qualified, but its .62 EF complies with the 2015 NACEA regulations.

Richard Reed at rates Rheem as a 3-star brand, about mid-grade. User feedback for the Rheem XG40T09HE40U0 is strong at, the primary retailer for this model. It earns a 4.5-star rating following more than 320 reviews, though some of those reviews were originally posted at Rheem's web site, with 95 percent of owners giving it a recommendation. The 40-gallon capacity is fine for families of two to four people. The XG40T09HE40U0 has low NOx emissions and is rated for altitudes of up to 10,200 feet. Rheem provides  an excellent warranty for a lower-priced water heater, at 9 years for parts and two years for labor. This water heater is just a touch smaller than the Whirlpool 40T12-40DNG (at 60.25 inches tall and 19.5 inches wide versus 64.25 inches tall and 19.75 inches wide for the Whirlpool), so it might be a better fit if installation space is tight. 

Condensing gas water heaters

A condensing gas water heater works much like a standard water heater, but with a design change that can greatly improve efficiency. As explained at the Energy Star website, a standard gas heater vents the exhaust from its burner directly out to a chimney or vent. In a condensing gas heater, those gases, and the heat they carry, are instead redirected into a heat exchanger (a coil or similar structure) that runs through the body of the water heater. This heat exchanger becomes a supplemental heat source, heating the water in conjunction with the burner, resulting in higher overall efficiency and lower fuel costs (by about 25 percent).

While the water heaters above meet the 2015 NACEA regulations, if you are looking for a larger storage tank gas water heater, above 55 gallons, those regulations will pretty much limit your choices to a condensing design. Though these gas heaters cost more than conventional storage tank models, the energy savings makes them worth considering even if you are considering a smaller (sub 55-gallon) capacity.

Condensing gas heater technology is relatively new, however, and there are few available models and even fewer available reviews. One exception is the Vertex line from AO Smith. These condensing gas water heaters are available in 50- and 75-gallon capacities, and we saw some good feedback for the 50-gallon AO Smith GDHE-50-NG (Est. $2,200). It draws a poor rating based on just a handful of reviews at, but fares far better elsewhere. At, the GDHE-50-NG draws nearly 100 reviews and a 4.8-star rating. Around 98 percent say they would recommend the gas water heater to a friend.

Performance is impressive -- and so is efficiency. The AO Smith Vertex GDHE-50-NG is Energy Star Qualified and boasts a thermal efficiency of 96 percent. The company claims that it produces enough hot water to run 3.4 showers at a time or unlimited back-to-back showers, and reviews seem to back this up. The gas burner is a low NOx design and the unit is backed by a 6 year warranty.

Elsewhere in this report:

Best Water Heaters | Best Electric Water Heaters | Best Tankless Water Heaters | Buying Guide | Our Sources

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