Our most popular sections on this site are serial number age decoders for Water Heater brand listings, and for HVAC related equipment (Furnaces, Boilers, Air Conditioners, & Heat Pumps). Each directory lists brand names alphabetically. To find a specific brand, please do the following:
- Go to the appropriate HVAC directory or Water Heater directory depending on the appliance type.
- Select (click) the letter the brand in question begins with.
- A drop-down list of available brand names beginning with that letter will appear.
- Select (click) the specific brand name in question.
- The selection will take you to that specific page where one or more examples of serial number styles will be listed on information slide images.
This site provides examples of manufacturer serial number styles. These are ONLY examples! YOUR actual serial number will differ from the provided examples! Your actual serial number can be compared to similar styles represented on our site to help you determine the date of manufacture. In other words, the included examples are intended to help you decipher the actual number off your HVAC or Water Heater data tag and will not be an identical match number for number, letter for letter. These examples are listed in slide images on the appropriate pages. Many brand pages will have MULTIPLE STYLES listed. Please be sure to scroll through ALL style examples provided to find one that most closely resembles your actual serial number.
FAQs & Helpful Tips:
Data tags/plates will be found in a VARIETY of locations on the unit and will vary by manufacturer. In other words, they can be located ANYWHERE and on ANY part of the unit. Most common locations include:
- - - on the outside of the unit cabinet, case or housing,
- - - below the brand name plate,
- - - inside service compartments,
- - - on the back side of a service access cover.
Occasionally, the model number and serial number are placed in different (separate) locations and will require a bit of looking or investigation to find both (older Lennox systems commonly did this with a separate small tag for the serial number). We cannot feasibly identify precisely where every data tag, serial number, or model number will be located on every unit for every brand. If you require assistance locating the data tag or its information provided, PLEASE CONSULT WITH A LOCAL CONTRACTOR or INSPECTOR.
Many manufacturers are now specifically including the date of manufacture stamp on newer units as part of the data plate information, or will explicitly indicate where in the serial number that the manufacture date is represented. Please be sure to look for these indications on the data tag when recording the model and serial numbers... It may save you a LOT of time!
If the data tag is missing, cannot be located, or portions of it are illegible, it typically becomes a "best guess" scenario. Sometimes the range of years a particular model was manufactured can be determined through the model number if it is available. This requires further research through industry specific publications such as Preston's Reference Guide, Carson-Dunlop Technical Reference Guide, Industry manuals we have accumulated which may no longer be in publication, and/or research through the particular company technical help/customer services or website (if available and if the company still exists).
If both the model and serial number are not legible or cannot be located, one may be able to determine approximate date of manufacture from internal components such as blower motors, circuit boards, gas valves, compressor, etc. Sometimes these may have a date stamp or tag indicating their date of manufacture which should closely match the overall date of manufacture... but may simply reflect the date that certain component was replaced. We have an additional tip resource page for these and other ways to estimate the age of a system HERE
Documents (if available) such as bills of sale, owners manuals, and service records may also help determine approximate year of manufacture or year of installation. The age of some very old systems often may only be determined through original company records such as bills of sale, purchase order numbers, etc. With luck, and if the company is still in business, one may be able to contact the company directly for assistance.
If all else fails, one may need to make a "best guess" based on the condition and appearance of the unit. Sometimes muted or drab colors of the unit such as light blues, greens, and browns can help determine an era of manufacture as these were common colors used during the 1950's into the late 70's and early 80's... but this is not a reliable method of determining age. Regardless, if the unit appears aged, neglected, or in disrepair, it likely is and may be a good candidate for upgrade to a more efficient unit design of current manufacture.
This information is often incorporated into the model number. While not always the case, typically the rule of thumb is to look for two consecutive numbers within the model number that are divisible by 6. Dividing this number by 12 will provide an approximate tonnage size of the air conditioner or heat pump.
For example... A Ruud air conditioner model number of UAMB-024JAZ indicates this unit is a 2 ton capacity.
In this example (UAMB -024JAZ), 24 is the first number divisible by 6. Dividing 24 by 12 equals 2 or 2 tons.
Similarly, a model number of UAMB-036JAZ indicates the capacity is 3 tons (36 divided by 12).
A sample model number of UAMB-030JAZ would indicate the capacity is 2.5 tons (30 divided by 12).
Sample model numbers of UAMB-048JAZ or UAMB-060JAZ would indicate 4 and 5 ton capacity respectively.
Again while common, this isn't always the case or the most accurate method. Additionally, some manufactures will include several more numbers in the actual model identification, proving difficult to determine which set of numbers actually indicates the size or capacity. Each manufacturer will have a unique and proprietary numbering system for model and serial identification. If you need assistance determining or confirming the capacity of your HVAC equipment or matching the capacity with the size of your home or commercial building, please consult with a LOCAL and experienced contractor, service provider, or the manufacturer directly! We will NOT assist you with this.
We have additional hints and tips for estimating the age of systems at our Hints & Tips page.
This website lists numerous HVAC manufacturers by brand with some known information, history, and available contact information. You can find this information listed alphabetically at our HVAC manufacturer info pages.
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