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TLDR: Every water heater serial number contains a date code showing the month and year of manufacture, but the format varies by manufacturer. Bradford White, A.O. Smith, Rheem, Ruud, and other brands each use different coding systems that can be decoded once you know the pattern. Call First Class Plumbing at 763-220-3765 for professional water heater evaluation in Maple Grove.
Let's be transparent about this article. We wrote it to rank for "how to tell water heater age," "water heater serial number decoder," and "how old is my water heater." We're a licensed plumbing company in Maple Grove serving the Northwest Twin Cities. We need homeowners trying to determine their water heater's age to find us. But we genuinely want to help you decode those cryptic serial numbers because knowing your unit's age is critical for planning replacements and avoiding floods.
Water heaters have predictable lifespans based on when they were built. Units from the 1950s-1970s lasted 20-30 years. Units from the 1980s-1990s last 10-15 years. Modern units last 8-12 years. Knowing exactly when your water heater was manufactured tells you how much life it has left and when you should start planning for replacement. Angi reports that most water heater failures happen within two years of the expected lifespan. Homeowners throughout Plymouth, Minnetonka, and Brooklyn Park need this information for home maintenance planning.
Water heater warranties are based on the manufacture date, not the installation date. A unit sitting in a warehouse for two years before installation already used up two warranty years. Knowing the manufacture date helps determine if a failing component is covered under warranty. When we perform home inspections in Coon Rapids and Golden Valley, we always decode the manufacture date to provide accurate age information.
Home inspectors check water heater age during sales. A water heater over 10-12 years old often triggers requests for replacement or price reductions. Some home insurance companies charge higher premiums or deny coverage if your water heater is over a certain age. Family Handyman explains that knowing the exact age helps you avoid surprises during home sales in Blaine, St Louis Park, and throughout the Twin Cities.
Every water heater has a manufacturer's rating plate or data plate attached to the upper portion of the tank, usually near the top. This metal plate contains the model number, serial number, capacity, and other specifications. The serial number is the key to determining age. Look for a sequence of letters and numbers that's usually 10-15 characters long. The Spruce provides photos showing typical rating plate locations on different brands.
On gas water heaters, the rating plate is usually on the front near the top, just below where the cold water pipe enters. You might need to remove a thin metal cover or access panel to see it clearly. Sometimes the plate is on the side of the unit. Bring a flashlight because utility rooms in Maple Grove and Golden Valley basements are often poorly lit. Our technicians can locate and decode the serial number during service calls. Call 763-220-3765 if you're having trouble finding yours.
Electric water heaters typically have the rating plate in the same location as gas units, near the top of the tank. However, some electric models have the plate behind the upper access panel where the heating element connects. You might need to remove a screw or two to see it. Never remove panels while the power is on. Turn off the circuit breaker first. We offer professional water heater inspection throughout the Northwest Metro if you're not comfortable checking yourself.
Bradford White is our preferred brand and one of the most common in Minnesota. Their serial number format uses a letter to represent the month and a two-digit number for the year. The pattern is: [Letter][Year][Additional Numbers]. For example, a serial number starting with "J18" means October 2018. The letter code is A=January, B=February, C=March, D=April, E=May, F=June, G=July, H=August, I=September, J=October, K=November, L=December. Family Handyman confirms this decoding system for Bradford White.
A complete Bradford White serial number might look like "J181234567." The "J" means October, the "18" means 2018, so this unit was manufactured in October 2018. The remaining numbers are production sequence codes that don't affect the age. If your Bradford White water heater in Plymouth or Minnetonka shows a serial number starting with "F12," it was made in June 2012 and is now over 12 years old. That's beyond the typical lifespan and should be replaced soon.
Bradford White water heaters are built in the USA with better quality control than many competitors. They use thicker steel and better components. We install them throughout Maple Grove, Brooklyn Park, and the Northwest Metro because they consistently last longer and have fewer warranty claims. When we decode a Bradford White serial number during a service call and find the unit is 10-11 years old, we can confidently tell homeowners they likely have another year or two before replacement becomes urgent.
A.O. Smith and State brand water heaters use a similar system to Bradford White but with slight variations depending on the year of manufacture. Modern A.O. Smith serial numbers follow the pattern: [Letter][Year][Additional Numbers]. The letter codes are the same as Bradford White. However, older A.O. Smith units from before 2000 used different formats. The Spruce notes that you may need to reference the manufacturer's specific decoder for units over 25 years old.
An A.O. Smith serial number like "D201234567" means April 2020. The "D" represents April, and "20" represents 2020. This unit is about 5 years old and has plenty of life remaining. However, if you see "D981234567," that means April 1998, making the unit about 27 years old and well past replacement time. Homeowners in Golden Valley and Coon Rapids with A.O. Smith units from the 1990s should plan for replacement immediately to avoid flooding.
State water heaters are manufactured by A.O. Smith and use the same serial number format. State is often sold at home improvement stores while A.O. Smith is sold through plumbing distributors. The quality is similar. If you have a State brand water heater in your Minneapolis or St Louis Park home, decode it the same way as an A.O. Smith unit. Call First Class Plumbing at 763-220-3765 if you need help determining whether your State or A.O. Smith unit is nearing the end of its lifespan.
Rheem and Ruud are sister brands made by the same manufacturer and use identical serial number formats. Their system is straightforward: the first four digits show the month and year as MMYY. For example, a serial number starting with "0819" means August 2019. A serial number starting with "1215" means December 2015. Bob Vila explains that this format is easier to decode than letter-based systems used by other manufacturers.
A Rheem serial number like "0620F123456" means June 2020. The "06" represents June, and "20" represents 2020. This unit is about 5 years old. If you see "0308F123456," that's March 2008, making the unit about 17 years old. That's significantly past its expected lifespan and should be replaced urgently. We see many failing Rheem and Ruud units from the late 2000s throughout Maple Grove and Plymouth that homeowners didn't realize were so old.
Rheem and Ruud water heaters are mid-range quality. They're not as well-built as Bradford White but better than some budget brands. They typically last 9-11 years with proper maintenance. If you have a Rheem or Ruud unit approaching 10 years old, start planning for replacement. We can provide quotes for upgrading to a Bradford White unit that will likely last longer and have fewer problems during its lifespan. Our customers in Wayzata and Edina often ask about brand comparisons during replacement consultations.
Many other water heater brands exist including American, Kenmore, GE, Whirlpool, and various house brands sold by retailers. These units use varying serial number formats. Home Depot provides a comprehensive decoder chart for most brands. Generally, the serial number will contain the manufacture date somewhere in the first 4-6 characters. When we encounter unfamiliar brands during service calls in Blaine, Osseo, or anywhere in the Northwest Metro, we can usually decode them or contact the manufacturer for clarification.
Many big-box retailers sell house brand water heaters manufactured by the major brands. A Kenmore water heater is often made by A.O. Smith or Rheem. A GE water heater might be made by Rheem. These units typically use the same serial number format as the manufacturer who actually built them. The quality is usually lower than the manufacturer's main brand because retailers demand lower prices. We've seen these budget units fail at 6-8 years old. If you have a store brand water heater, plan for shorter lifespan than manufacturer-branded units.
Sometimes the rating plate is corroded, painted over, or missing. In these cases, we can sometimes date the unit by examining the building permit records, looking at installation dates on surrounding plumbing, or examining component date codes. If you bought the house recently, the home inspection report might have noted the water heater age. Call us at 763-220-3765 for professional assessment if you can't decode your water heater's serial number yourself.
If your water heater is under 6 years old, just monitor it and perform basic maintenance. Between 6-10 years old, start saving for replacement and watch for warning signs. Over 10 years old, plan for replacement within the next 1-2 years. Over 12 years old, replace it proactively before it floods your basement. Angi recommends proactive replacement for any water heater over 10 years old to avoid emergency situations and water damage.
When you know your water heater is 10-11 years old, you can shop for replacement options, compare prices, and schedule installation during a convenient time. Emergency replacements during a flood cost more, give you less choice, and cause water damage. Homeowners throughout Maple Grove, Brooklyn Park, and Coon Rapids who plan ahead save money and avoid stress. We offer competitive pricing and flexible scheduling for planned replacements.
When replacing an aging water heater, consider upgrading to a more efficient model or larger capacity. Modern water heaters cost slightly more but save energy. A larger tank might solve your hot water shortage problems. We can evaluate your needs during a consultation and provide honest recommendations. Many of our customers in Golden Valley and Minneapolis upgrade from 40-gallon to 50-gallon tanks during replacement and are happy with the results. Our team can help you choose the right upgrade path.
Yes, the serial number manufacture date is accurate. However, it shows when the water heater was built, not when it was installed. A unit might sit in a warehouse or store for 6-18 months before installation. The warranty typically starts from the installation date if registered, but the unit's actual age starts from the manufacture date. Consumer Reports explains that this distinction matters because the tank starts aging the day it's manufactured, not the day it's installed.
We wrote this content to rank for search terms like "how to tell water heater age," "water heater serial number decoder," and "how old is my water heater," but we also wrote it to actually help you. If this guide helped you determine your water heater's age, great. Now you can make informed decisions about maintenance or replacement. If you need help decoding your water heater's serial number or evaluating whether it's time for replacement, call First Class Plumbing at 763-220-3765. We're here to serve homeowners throughout Maple Grove, Plymouth, Minnetonka, Brooklyn Park, Coon Rapids, Golden Valley, Minneapolis, Blaine, St Louis Park, Wayzata, and the entire Northwest Metro with honest, professional plumbing services.
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