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AGE of WATER HEATERS
ALTERNATIVE HOT WATER SOURCES
ANODES & DIP TUBES on WATER HEATERS
ANTI SCALD VALVES
APPLIANCE EFFICIENCY RATINGS
AQUASTAT CONTROL Functions
BACKDRAFTING HEATING EQUIPMENT
BACKFLOW PREVENTER, HEATER WATER FEEDER
CARBON MONOXIDE - CO
CHECK VALVES, WATER SUPPLY
CLOGGED SUPPLY PIPING
CROSS CONNECTIONS, PLUMBING
DEBRIS in WATER SUPPLY, Water Heater
DRAIN a WATER HEATER TANK
ELECTRIC WATER HEATERS
FLOODED WATER HEATER REPAIR
FREEZE-PROOF A BUILDING
GALVANIC SCALE & METAL CORROSION
GAS BURNER Flame & Noise Defects
GAS FIRED WATER HEATERS
GAS PIPING, VALVES, CONTROLS
HEATING COST SAVINGS METHODS
HOT WATER SUPPLY
HOT WATER IMPROVEMENTS
HOT WATER DELIVERY SPEED UP
HOT WATER EFFICIENCY IMPROVEMENT
HOT WATER PRESSURE EXPANSION RATE
HOT WATER PRESSURE LOSS
HOT WATER PROBLEM DIAGNOSIS
HOT WATER QUANTITY IMPROVEMENT
HYDROGEN SULFIDE GAS
INDIRECT FIRED WATER HEATERS
MANUALS & PARTS GUIDES - HVAC
MIXING / ANTI-SCALD VALVES
NO HEAT - NO HOT WATER: HEATER DIAGNOSIS
NOISE, WATER HEATER
ODORS IN WATER
PIPING IN buildings, Clogs Leaks Types
RELIEF VALVE LEAKS
RELIEF VALVES - Water Heaters
SCALE REMOVAL, WATER HEATERS
SEWER GAS ODORS
SOLAR HOT WATER HEATERS
TANKLESS WATER HEATERS
THERMAL EXPANSION of HOT WATER
THERMOSTATS, WATER HEATER
TIMERS for ELECTRIC WATER HEATERS
WATER HEATER ALTERNATIVES
WATER HEATER ANODES, DIP TUBES
WATER HEATER AIR INLET
WATER HEATER DEBRIS FLUSH
WATER HEATER DRAIN PROCEDURE
WATER HEATER EFFICIENCY
WATER HEATER FLUSH PROCEDURE
WATER HEATER NOISES
WATER HEATER PROBLEM DIAGNOSIS
WATER HEATER PROPERTIES
WATER HEATER SCALE
WATER HEATER SAFETY
WATER HEATERS for HOME HEATING USE?
WATER ODORS, CAUSE CURE
WATER PIPES, Clogs Leaks Types
WATER PRESSURE TOO HIGH: DANGERS
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER QUANTITY IMPROVEMENT
WATER SOFTENERS & CONDITIONERS
WINTERIZE A BUILDING
Here we explain how to determine the age of a water heater, we provide a chart that decodes the year of manufacture of water heaters, and we discuss the conditions, maintenance, and factors that affect how long a water heater can be expected to last.
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Our photo at page top shows an oil fired water heater with a backpressure problem and other safety concerns like a missing extension tube on that relief valve, and maybe a missing draft regulator and perhaps an oil line that is not protected from damage.
The data tags (containing the water heater's age) for this heater are hidden by its insulating blanket. Readers who need to determine the age of air conditioning and heat pump equipment should see A/C DATA TAGS.
How can we determine the age of a residential water heater? By looking at and decoding data on the water heater's label.
Nearly all modern water heaters, electric, oil fired, or gas fired, include data tags and stickers that indicate the year and month of manufacture of the water heater.
That doesn't tell you exactly when a water heater was installed in a particular building but it does indicate the age of the water heater itself.
However some manufacturers encode the year and month of manufacture of their water heater in the product's serial number so that the water heater age is not immediately obvious.
Our photo (above left) shows a gas-fired Rheem™ water heater. The label containing the unit's serial number is probably at the water heater top left. The label above the gas control at the water heater bottom typically contains water heater lighting instructions.
Carson Dunlop provide a most-comprehensive Technical Reference Guide to heating and cooling equipment manufacturers that includes water heater manufacturers. For an encyclopedic reference including manufacturers, history, contact information, and serial number decoding we recommend this book.
Scott LeMarr has generously shared his free Water Heater Age Determination Chart that decodes both furnace age and water heater age. He includes data for many brands of water heater, including hot water systems produced by the manufacturers listed just below.
Water heater age is encoded in data on the information label on these water heaters: Ambassador water heaters, American water heaters, ACE water heaters, A.O. Smith water heaters, Apollo, Aqua Temp, Aqua Therm, Best water heaters, Bosch water heaters,Bradford White, Cafos, Champion, Crosley, Energy Saver, Envirotemp water heaters, GE water heaters, Glascote water heaters, Golden Knight water heaters, GSW, Hotpoint water heaters, JC Penny, Jetglas, JW or John Wood, Kenmore water heaters (Sears Brand), Lochinvar, Lowes, Mainstream, Maytag water heaters, Montgomery Wards, Knight, PermGlas, Reliance water heaters, Revere, Rheem water heaters, Rheem/Rudd/Richmond water heaters, Rinnai, Security, Shamrock water heaters, Standard water heaters, State/Reliance/Sears brand water heaters, Thermo-King, Vanguard water heaters, US Craftsmaster, US Water Heaters, and Whirlpool water heaters.
Here is A Chart that Decodes the Date of Manufacture of a Hot Water Heater
Our photo (above-left) is from the A.O. Smith EnergySaver water heater in our laboratory.
The unit's serial number, MM02-2147713-260 identifies the model and its date of manufacture. The "02" following MM indicates that this unit (in our laboratory) was manufactured in 2002 and the -2 following the MM02- decodes to February.
In a second example, Rheem water heaters provide first the month MM and then the year in the first four digits of the water heater's serial number.
The label shown here includes 0884 at the beginning of the serial number - August 1984.
Mr. LeMarr points out that in the U.S. the remaining actual manufacturers of domestic hot water heater heaters are American, A.O. Smith, Bradford White, and Rheem companies, though their products may be branded among the many names listed just above. LeMarr also informs us that water heaters made in Japan and China are entering the U.S. market. Whenever we have updates to this water heater age and identification chart we'll post the latest version of it here.
How Long will My Water Heater Last? What Determines Water Heater Life?
The chronological age of a water heater (how long ago was it made) is hardly the only factor that determines how long the water heater will last. Here are some other factors that affect the life of a water heater:
Our next photo (left) shows how a tall water heater was shoe-horned into a low crawl space by digging out a pit to allow the tank to stand upright. This heater is also likely to be exposed to flooding.
We have also seen water heaters placed horizontally to fit into a tight crawl space - a possibly dangerous installation. Unless the manufacturer has specifically designed a water heater to mount horizontally there is risk that the tank or other components will not be properly supported and the system will be damaged and unsafe.
In sum, improper location or improper position of a water heater, such as mounting some water heaters horizontally or locating a water heater in a flood prone location or where it can't be properly serviced or vented can lead to early failure of the heater as well as voiding the manufacturer's warranty.
Also see Water Heater Life Expectancy Comparisons for a short list of other factors that determine the life expectancy of a water heater.
Type of water heater tank and water heater warranty - modern "glass lined" water tanks are coated to resist corrosion. The manufacturer's warranty is a clue to how long the company expects their water heater tank to last.
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