The A. O. Smith GDHE-50 Vertex 100 is the more efficient of two models in the Vertex series, with outstanding 0.96 efficiency -- achievable only with condensing technology that makes it essentially a hybrid water heater. It's more energy-efficient and provides a higher flow of hot water than almost all tankless water heaters, and costs much less to install in an existing home. This makes it worth considering as a replacement for an inefficient electric water heater, and it produces so much hot water -- 169 gallons for a household's peak usage hour -- that it can replace two regular gas water heaters. The initial price may seem daunting, but unlike most gas tank-style water heaters, the Vertex is eligible for the 30 percent federal tax credit, the state "cash for appliances" rebate and any other Energy Star incentives. If you like the idea of cutting future fuel bills but have an all-electric home, consider the GE GeoSpring Hybrid GE H50DNSRSA (*Est. $1,440).
We found the most objective tests of the A. O. Smith Vertex water heater at ConsumerReports.org, though their tests aren't yet complete. The Journal of Light Construction compares the Vertex with other super-efficient condensing water heaters, and a forum at PlumbingZone.com discusses how actual customers are responding to it. The Vertex also gets brief reviews at Fine Homebuilding and 411plumb.com. Two surveys of builders and contractors evaluate A. O. Smith as a brand, ranking it in comparison with other water heater brands. The survey at BuilderOnline.org is more recent, but the one at J. D. Power and Associates covers other factors in addition to product quality. A video review at Popular Mechanics explains a bit about how the Vertex works, highlights its advantages and shows it actually installed.
Our Sources: AO Smith Water Heater Reviews
While testing gas tankless water heaters, ConsumerReports.org editors also test the A. O. Smith Vertex water heater. However, no specific ratings or rankings are provided, and the details of testing are scanty.
Review: Tankless Water Heaters, Editors of ConsumerReports.org, October 2008
2. Journal of Light Construction
This review aimed at plumbers recommends the A. O. Smith Vertex as one of the least expensive water heaters that uses condensing technology, noting that it's much easier to install as a replacement for an electric water heater, compared with gas tankless heaters.
Review: Condensing Storage Water Heaters, Jim Lunt, June 2009
Plumbers discuss the Vertex water heater in detail here, noting that it heats water extremely fast; one says his customer had a full tank of hot water ready before he'd finished writing the bill for the installation. Another says he installed it to replace two 75-gallon gas water heaters.
Review: A. O. Smith Vertex Water Heater, Contributors to PlumbingZone.com, November 2009
4. Fine Homebuilding
The A. O. Smith Vertex is among several specific water heaters recommended in this article on saving money on heating water.
Review: Cheaper Hot Water, Dave Yates, Oct. 15, 2008
This single-product review by a plumber recommends the A. O. Smith Vertex water heater but doesn't document any testing. The reviewer does note that in addition to other incentives, the Vertex is eligible for Weatherization Assistance Program grants (up to $6,500) for low-income homeowners who meet the requirements.
Review: A.O. Smith GDHE-50 Vertex 100 Power Direct Vent Gas Water Heater Review, Editor of 411plumb.com
A. O. Smith is one of the water-heater brands that ranks toward the top for quality in this survey of over 3,400 builders and contractors.
Review: 2008 Builder Brand Study, Editors of BuilderOnline.org, March 31, 2008
7. J.D. Power and Associates
This survey of nearly 900 contractors and subcontractors ranks A. O. Smith below average based on six factors. Warranty and repair service, ordering process, credit/billing, delivery, price, sales and marketing support as well as the product itself are evaluated.
Review: HVAC and Water Heater/Boiler Subcontractor Satisfaction Study, Editors of J.D. Power and Associates, September 2006
This video review covers a slightly less efficient Vertex model but notes that it's still more efficient than most gas tankless water heaters. The review explains how the Vertex works and highlights its advantages.
Review: Jay's Green Garage: Leno Installs a Superefficient Water Heater, Ben Stewart, Oct. 1, 2009