EmailBest Reviewed
Water Heaters
- Budget electric water heater Kenmore 32656 Power Miser 6 *Est. $290
- Energy-efficient gas water heater Kenmore 33159 HydroSense *Est. $600
- Energy-efficient electric water heater Rheem/Ruud Marathon MSR50245 *Est. $1100
- Heat pump add-on AirGenerate AirTap A7 *Est. $700
- Whole-house tankless water heater Takagi Flash T-H1 *Est. $2800
- Small point-of-use water heater Bosch Ariston GL4 *Est. $170
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Whole-house tankless water heater
- Eligible for federal tax credit
- Energy efficient
- Durable (20-year lifespan)
- One unit can supply whole house
- High installation costs
- Experienced contractors required
- Cold water "sandwich" effect
March 2009. Tankless water heaters last at least 20 years on average, and since there's no tank to leak, can be repaired easily. The Takagi Flash T-H1 provides an unlimited supply of hot water at a rate of 3.9 to 7.7 gallons per minute, depending on the temperature of the incoming water. It can supply the whole house: One review says 10 people can take showers at the same time. As with all tankless water heaters, expert system design and installation are crucial. If the water heater is located too far from the faucets it serves, or regular maintenance isn't performed, owners say the water heater won't perform well. And as with all tankless systems, users report that there's sometimes a "sandwich" of cold water after an initial burst of hot water. Although the Takagi tankless heater qualifies for a federal tax credit, it's still expensive. Installation costs can also be high, especially if you need plumbing and electrical modifications. Furthermore, reviewers including Consumer Reports say that they payback period could be 20 years or more based on energy savings -- not counting the cost of the unit itself.
We found the best information on tankless water heaters at FineHomebuilding.com, where one article shows how to design a water system that eliminates the most common problems, and another shows when tankless water heaters are the best option. Jim Dulley's review of tankless water heaters covers specific brands, and an article in PMEngineer.com describes how the Takagi Flash T-H1 is used in vacation homes in Florida for heating as well as hot water. We found quite a few other articles and comments that help clarify why tankless water heaters are so satisfactory in some situations, frustrating in others.
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Our Sources
1. Fine HomebuildingDetails/Subscribe
This review is the one of several recent articles on hot water heaters in FineHomebuilding.com, a print and online publication aimed at professional builders, but also valuable for do-it-yourself homeowners. This specific article solves several problems often encountered with tankless water heaters, with cost estimates and full details. Another article, also available online via free trial subscription, covers "Tankless vs. Tank Water Heaters."
Review: Why Add a Tank to a Tankless Water Heater?, Michael Chandler, Nov. 2007
2. Sensible HomeDetails/Subscribe
This review of tankless water heaters recommends several brands, including Takagi. The review includes the flow rate at temperatures ranging from 50 to 90 degrees Fahrenheit for five different Takagi models. Dulley notes that they can be installed indoors or out, with water temperature adjustable between 95 and 167 degrees.
Review: Tankless Water Heaters for Endless Showers, Energy Savings, James Dulley, 2007
This long article describes how a Florida vacation community uses Takagi Flash T-K1S tankless water heaters for supplying hot water not only to faucets, but for space heating as well. The cost was only $100 more than the amount originally budgeted for electric heat pumps, but the builder estimates that owners will have utility bills at least 50 percent lower than for an all-electric home. The tankless water heaters are big enough to supply 10 showers at once, ideal for vacation homes.
Review: Takagi Industrial USA -- Tankless Water Heaters Benefit Vacation Community, Editors of PMEngineer.com, May 2006
4. Database of State Incentives for Renewals and Efficiency
This state by state database can tell you the incentives available in your area for buying a more energy-efficient water heater.
Review: State Incentives for Renewals and Efficiency, July 2007
This online interactive tool calculates the lifetime energy savings for specific water heaters, but doesn't take into account the longer average lifetime of a tankless water heater. The website does have a detailed, well-written buyers' guide for tankless water heaters, but doesn't recommend specific brands or models.
Review: Untitled, U.S. Department of Energy editors, Mar. 2008
This excellent comparison review shows that soft water is an important factor in the energy effectiveness of tankless water heaters, because hard water rapidly deposits lime scale on the heat exchangers, making frequent maintenance essential. Though the review fails to take into account the longer life-expectancy of most tankless water heaters, it does document that they usually have a very long payback period.
Review: Tankless vs. Tank Type Storage Water Heater Efficiency Comparison Testing, Editors of PMEngineer.com, Jan. 7, 2005
7. Air-Conditioning, Heating and Refrigeration Institute
All the Takagi tankless water heaters are eligible for the 2008 income tax credit for installation in new homes constructed by the end of 2008. (Since this review, the credit has been extended by at least a year.)
Review: Tax Credit Eligible Equipment, Editors of Air-Conditioning, Heating and Refrigeration Institute, 2007
A survey of over a hundred households finds that installing gas tankless water heaters close to the points of use makes a huge difference in owners' satisfaction. In fact, all the owners are satisfied if they installed them close to the points of use, but only 61 percent are satisfied if they installed them in basements or attics.
Review: Attitude Survey among Participants in the Gas Network's Tankless Water Heater Program, Editors of Nexus Market Research, Oct. 2006
Residents of Berkeley, Calif., comment on their experiences with tankless water heaters, including the older Takagi T-K2, giving a good overview of the pros and cons of tankless water heaters in various situations.
Review: On-demand or Tankless Water Heater, Contributors to Berkeley Parents Network, May 2006
Two owners disagree here about the merits of a smaller Takagi tankless water heater, one praising its performance, the other reporting a breakdown after less than a year.
Review: Tankless Water Heating T-K Jr., Contributors to GreenerBuilding.org
