Maytag Natural Gas Water Heaters - Manual (Page 3)

Steps For Selecting a Natural Gas Water Heater
• Decide which type of natural gas water heater will work best for your home.
• Determine the size you need by using the first hour recovery ratings.
• Compare energy eff i c i e n c y, operating costs and purchase prices.
• Select the best venting option for your home.
• Be sure that the models you are considering are design-certified by a nationally recognized testing laboratory.
• Choose a qualified installer.
• Maintain and use your water heater properly.
Types Of Natural Gas Water Heaters
Stand-alone natural gas water heaters are available in two
general types: storage and tankless. The most common type is a
s t o r a g e water heater, which combines a gas burner and an insulated
tank to store hot water. A t a n k l e s s water heater uses a natural gas
burner to heat water as you need it. It’s sometimes referred to as an
instantaneous water heater.
Other types of water heaters that depend on the home’s heat-
ing system are also available. One is a combination system that pro-
vides forced-air space heating and water heating, sometimes called a
c o m b o - h e a t e r. Another uses heat from a hot water or steam space-heating system to run a separate hot water sys-
tem.
H e r e ’s a more detailed explanation of each:
Storage Water Heaters
Storage water heaters are the most popular type for residential use in the United States. Astorage water
heater takes cold water from the home’s water supply and moves it to the bottom of the tank, where it’s heated by a
gas burner controlled by a thermostat. Hot water is lighter than cold water, so the heated water rises to the top of the
tank, where a delivery pipe sends it where it’s needed. When hot water leaves the tank and colder water replaces it in
the bottom of the tank, the burner automatically comes on again to heat the new water. The burner will also come on if
the water in the tank drops below a pre-set temperature. Arelief valve protects against temperature or pressure that is
too high for the tank.
The insulated storage tanks are usually made of steel, and are lined inside with glass or another material to
prevent corrosion. The tanks also contain an "anode" rod, composed of one or more metals, which attracts corrosion
away from the rest of the tank’s components.
Because the water in the storage tank is kept at a constant temperature 24 hours a day, some heat is lost
even when no hot water faucet is on. This is called stand-by heat loss. Newer water heaters have more insulation to
help reduce stand-by heat loss.
The natural gas burner produces some combustion byproducts -- primarily water vapor and carbon dioxide.
These byproducts are vented to the outdoors through a chimney, flue or side-wall vent. The burner is lit by a standing
pilot light or by an electronic or spark ignition.
Storage water heaters are free-standing, and their wide variety of venting configurations gives homeowners
many choices for location and installation. Some models can even be installed outdoors without any kind of housing or
c o v e r. They’re a good choice for homes that are converting to a natural gas water heating system from other types,
because the installation is relatively simple.
Tankless or Instantaneous Water Heaters
Tankless water heaters can be wall-mounted or free-standing, and are usually located close to where the hot
water is used. These compact units have a gas burner that ignites when the hot water faucet is turned on. The burner
heats the water instantaneously as it’s being used. When the faucet is turned off, the burner shuts off. Tankless mod-
els can provide from 2 to 4 gallons of hot water per minute.
Because these tankless units do not store water, they have no stand-by heat loss. This can reduce energy
consumption by 20 to 30 percent, compared with storage water heaters, according to the U.S. Department of Energy
( D O E ) .
Instantaneous water heaters can be installed outdoors as well as indoors, and are suitable for vacation
homes, cabins or recreational vehicles. They are not the best choice, however, for a family that needs large quantities
of hot water during a short time period -- multiple morning showers, for example.
C o m b o - h e a t e r s
Combination water-heating/space-heating units are compact systems that require only one unit to heat water
and heat rooms. They are ideal if the space for a water heater and heating system is small.
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Storage water heaters
a re the most popular
type for residential use
in the United States.