How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manufactured and modular homes
How do I determine the age of my air conditioner if the serial number is missing or not legible?
Thursday, September 7, 2023
If the data plate on the air conditioner is missing or so faded that it is no longer readable, you already have part of the answer. It’s a least 10 years old. But, if you need a more specific age, here’s four ways to find it:
1) Check building permits. You may be able to get the date of the permit for replacement of the system from your local building department. If they don’t have a permit on file, then the unit is either original to the construction of the home or was replaced without a permit.
2) Check data plate at other half of system. If it is a split system, and both parts of the system have the same manufactuerer and paint color on the cabinet. So check the air handler data plate if the one on the condenser is illegible, or vice-versa.
3) Ask for homeowner’s paperwork. Many homeowners keep the owner’s manual and payment receipt for their system. However, relying on only the homeowner’s memory for the age if that’s not available can be a mistake. “We just replaced it a few years ago” sometimes turns out be 10 or more after age is verified by another means, especially for seniors.
4) Condition of condenser - Condensers (outdoor units) age at different rates according the weather and sun exposure where they are located. But an experienced home inspector can provide an approximate age based on condition. Air handlers are more difficult to age based on condition, but there is usually more than one data plate to check for serial numbers.
To determine other key specs of your HVAC system, see one of these other blog posts:
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Field Guide for Home Inspectors, a quick reference for finding the age of 154 brands of HVAC systems, water heaters, and electrical panels, plus 210 code standards for site-built and manufactured homes, and the life expectancy rating of 195 home components. Available at amazon.com for $19.95.
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To learn more about heating and air conditioning systems, see these other blog posts:
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