CRS Referred Products
Water Heating
If you're like most people, you don't even think about hot water until your
water heater fails. And by then, you may not have time to shop around, or even
consider the choices you have. Here's some information that will help you make a
wise decision when the time comes.
Storage water heaters
You probably have a storage water heater. These are the most popular water
heaters in the United States. They are reliable and efficient. Whether gas or
electric, storage water heaters use the same principal and basic design. Cold
water comes in at the top and is directed to the bottom of the tank through in a
"dip tube." A gas burner or electric element heats the water. As you draw hot
water, cold water replaces it and is heated by the burner or element. Safety
sensors and valves regulate temperature and pressure. Since electric water
heaters don't require venting, you can put them just about anywhere, and they
are generally less expensive to buy. However, they do cost significantly more in
the long run because electricity can cost up to 35-50 percent more than gas. Gas
water heaters need venting because of the by-products of combustion. Most gas
storage water heaters vent through a vertical pipe inside the tank, which also
helps to heat the water—the flue gases give off some of their heat to the water
in the tank. The pipe goes through your house to the roof, which limits these
water heaters' placement.
Some newer water heaters allow fan-assisted or direct venting through an
outside wall. Fan-assisted models can be placed as far as 40 feet away from an
outside wall. Direct-vent models, which rely on nature to do the venting, must
be no more than four feet from an outside wall. Combustion air—the air needed to
keep the gas flame going—is another consideration. In today's more tightly
weather-proofed homes, locating a water heater near the furnace, boiler, or
clothes dryer, or in a living area of the home, can place extraordinary demands
on indoor air.
Talk to your installation contractor about placement and fresh-air intake.
Never store household chemicals such as fabric softener, bleach, and detergent
near a gas water heater. Air flowing to the gas burner can carry traces of these
chemicals, which will accelerate corrosion of the combustion chamber, vent and
flue baffle.
Other choices
TANKLESS (On-Demand) WATER HEATERS use electricity or gas to heat water instantly when you
turn on the hot-water faucet, dishwasher or clothes washer. There's no tank to
install, but if you use hot water in more than one place at the same time,
you'll have to install separate heaters in the kitchen, bathrooms, and near the
clothes washer, which is costly. Also, they have a slow flow rate, about 2-4
gallons per minute. Another alternative is to use your home's heating system to
heat hot water. Called indirect systems, they run hot water in separate pipes
through the boiler. The water in the boiler, which is about 180°F, heats the
water in the pipes to normal household-use temperatures. The hot water is stored
in an insulated tank. If you have a highly efficient boiler heating system, an
indirect water heater may be the most economical way to heat water. In warm
weather, a thermostat triggers the boiler to go on when you run out of hot water
in the tank.
Repair or replace?
Storage water heater tanks typically last seven to 12 years, depending on the
chemicals in the water and the temperature setting (temperature settings above
130°F shorten the life of the tank). Leaks caused by corrosion can't be fixed,
but if you're just not getting hot water (or not enough), the problem may be the
electric element or gas burner. These can be replaced or fixed.
Maintenance
Your water heater is working every day of the year and needs regular
maintenance. Have a professional check key components such as the pressure and
temperature relief valves, shutoff valve, and, for a gas water heater, the gas
control and burner, every two or three years. You should also drain the sediment
that collects in the bottom of the tank every year. Follow the manufacturer's
instructions. Ask your contractor about earthquake straps and a safety drain
pan, too. As your water heater approaches its maximum life, give it a visual
once-over every month or so. Check for rust and small leaks. You can avoid a
major water disaster by replacing it before it fails.
Your needs
Bigger is not always better! Before you decide on a water-heating system, you
should think about how much hot water you actually use at any one time— multiple
showers in the morning, for example, or running the dishwasher and washing
machine at the same time. This is called the "first-hour rating" (FHR), and it's
a measure of the maximum amount of hot water that the system supplies in one
hour. Gas water heaters usually have higher FHRs than electric water heaters. If
your family requires an FHR of 65 gallons, for example, a 40-gallon gas water
heater will probably meet your needs; you'd need a 65-gallon electric water
heater to have the same FHR. So if you choose gas, you can purchase a smaller
water heater, which saves space and costs less to operate. Operating costs,
FHRs, and energy-related criteria are noted on the yellow EnergyGuide sticker on
water-heating systems. They are valuable tools in helping you make comparisons
among various systems and models.
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