Water heaters

Water Heater Buying Guide

You probably don't think about your water heater until a cold shower or a telltale puddle suggests you need a new one. How to choose? Most look alike on the outside. But a look inside tells a different story. Storage tanks cost less but tankless heaters save energy by only heating the water you draw.

Getting started

Before you shell out $500 or $600 for a storage-tank heater or up to $1,200 for a more-efficient tankless model, see whether the old water heater can be fixed.

While a corroded, leaking storage-tank model isn’t salvageable, a leaky drain valve or pressure-relief valve or a worn-out electric heating element can be repaired. A rule of thumb: Consider a repair if the labor cost (which warranties often exclude) averages less than $50 per year for each remaining year of coverage. Otherwise, put the $100 you’d pay just for the plumber’s service call toward a new unit, especially if yours is out of warranty.

Tankless water heaters save energy by heating only the water you draw. Many factors dictate the energy savings, including how much hot water you use and how often you use it. But these units can cost two or three times as much as a storage unit and can require expensive upgrades in gas- or electric-supply lines and venting.

The inside story

Most storage-tank and tankless water heaters look alike on the outside, but the innards tell a different story. Sawing open 18 gas and electric storage-tank models in our lab confirmed that paying a little more buys a better water heater.

The difference in price between models with a six- and a 12-year warranty is only $60 or $80 for electric models and $50 to $100 for gas units. Storage-tank water heaters with longer warranties typically have larger heating elements, thicker insulation, and thicker or longer corrosion-fighting metal rods, or anodes.

Manufacturer warranties on tankless water heaters we tested ranged from three to 12 years for the internal heat exchangers and two to six years for all other parts. As with storage-tank water heaters, the length or warranty is a good indication of internal build quality. Some tankless water heater manufacturers shorten the warranty in areas with hard water and when used in multiple family homes. Most tankless manufacturers also recommend that the units be serviced once a year by a qualified technician.

Long warranty coverage is especially important because warranties typically cover only the heater, not the $200 to $300 cost of installation. A long warranty is also desirable if you have hard water and use water softeners, which can speed up anode corrosion or cause scaling in the heat exchangers of tankless water heaters. One of our tankless water heaters had to be descaled at a cost of $344 for special tubing and the services of a plumber.

Calculating usage

Most water heaters are sold on the basis of how many gallons they hold. But the first-hour rating (FHR) for storage-tank water heaters and the gallons-per-minute rating (GPM) on tankless water heaters is more important, because it tells you how much hot water the heater can deliver during a set period of use. Use our free hot water calculators at http://www.consumerreports.org/hotwater to determine how specific tasks like showering and clothes washing will affect your peak usage.

Recent tougher federal energy standards require about 10 percent higher efficiency for gas water heaters and about 5 percent for electric models. The insulation added to meet those standards has made some heaters up to 4 inches wider, possibly a problem for installations in closets and other tight spots. (For added efficiency, consider adding insulation to hot-water pipes and the cold-water pipe exiting from the water heater.)

New 30-, 40-, and 50-gallon gas heaters are designed to prevent the heater’s flame from igniting flammable vapors in the room. But as with any fuel-burning appliance, you’ll still need smoke and carbon-monoxide detectors. Note that heaters are generally vented through the same chimney as a furnace or boiler. If you change venting for one appliance, you might need to change it for the other. Also, tankless water heaters’ higher combustion temperatures require installing Category 3 stainless-steel venting; the cost will vary with the length of the venting needed. (In warmer climates, tankless heaters can be installed outdoors to eliminate this cost.)

 
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