The first two numbers of the serial number are the year of manufacture for water heaters made by American Water Heater Company. So the data plate shown below indicates 2004. 

    American manufactures several different brands of its own, such as Proline and Craftmaster, along with others for companies and retailers like Whirlpool and Ace Hardware. Many have been discontinued for years, but a few older water heaters with these nameplates may still be around. If you look carefully at the bottom of the data plate, you will see the name of the actual manufacturer in fine print. This is important to look for, because some retailers have switched manufacturers for their brand over the years. Here’s a list:
• Ace water heaters
• American Hardware water heaters
• Apex water heaters
• Aquamatic water heaters
• Aqua Temp water heaters
• Aqua Therm water heaters
• Best or Best Deluxe water heaters
• Champion water heaters
• Deluxe water heaters
• Eagle water heaters
• Earl’s Energy Saver water heaters
• Envi-Ro-Temp water heaters
• Hotmaster water heaters
• Hotstream water heaters
• King-Cleen water heaters
• King-Line water heaters
• Master Plumber water heaters
• Nationaline water heaters
• Neptune water heaters
• Penguin water heaters
• Premier water heaters
• Quaker water heaters
• Quick-Flo water heaters
• Revere water heaters
• Riviera water heaters
• Sands water heaters
• Sentinel water heaters
• Service-Star water heaters
• Shamrock water heaters
• Special Deluxe water heaters
• Standard water heaters
• Super Eagle water heaters
• Sure-Fire water heaters
• Thoro-Clean water heaters
• Tru-Test water heaters
• Tru-Value water heaters
• U.S. Supply water heaters

    To determine the age of another manufacturer/brand of water heater, go to How do I determine the age of my water heater?

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Here’s links to a collection of more blog posts about WATER HEATERS:

• Are water heaters required to be raised off the floor? 

• Can a Temperature and Pressure Relief (TPR or T&P) valve be mounted to discharge horizontally?

• Where are gas water heaters not allowed to be installed?  

• Is the minimum size water heater inlet pipe 1/2" or 3/4" according to the building code? 

• Can you use a light switch for a water heater disconnect? 

• How can I tell if a water heater is HUD-approved for mobile/manufactured homes?

• Can you wire a 240-volt water heater with 120 volts? 

• Is it alright to have a shut-off valve on both the hot and cold water pipes at a water heater?  

• What is the minimum clearance to doors and windows for an outdoor tankless gas water heater? 

• What is required clearance for access and working space in front of an electric water heater? 

• Why is the water heater older than the house? 

• Does a water heater need a shut-off valve? 

• Why should a tankless water heater have an isolator/service valve kit installed?

• When was a gas water heater first required to be elevated 18 inches above a garage floor?  

• Can the temperature and pressure relief (TPR) valve discharge pipe for a mobile/manufactured home water heater terminate under the home? 

• What is the purpose of a thermostatic mixing valve above a water heater? 

• Does a tankless gas water heater still work with no electricity during a power outage?  

•  Why do water heaters have a sacrificial anode? 

• What is the difference between a manufactured/mobile home water heater and a regular water heater? 

• Does a tankless water heater require a pressure relief valve?

• When is a water heater drain pan required?

• Why is there water in my water heater drain pan?

• What does it mean when a water heater Temperature/Pressure Relief (TPR) discharge pipe is "trapped"? 

• Can I leave a gas water heater in place when remodeling a garage into a family room or bedroom? 

• Where do I find the water heater in a mobile home?

• Does a tankless water heater in an attic require a drain pan? 

• How does a hydronic heating system work?

• What is the difference between a regular water heater and a direct vent water heater? 

• What is the difference between a regular water heater and a power vent water heater?

• What is backdrafting at a gas water heater? 

• How do I determine if a water heater is gas or electric?

• What does it mean when a gas appliance (water heater, furnace, or range) has been "red tagged"?  

• What's the valve with the flip-up handle on the water heater for?

• Why is an older water heater an insurance problem?

   Visit our WATER HEATERS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.