The third and fourth numbers after the single letter in the serial number indicate the year of manufacture. It is also noted in the upper right of the manufacturer’s data plate, and the one shown below indicates the unit was manufactured in 2014.

    To find out the size of you Thermal Zone system in tons, go to our blog post How many tons is my Thermal Zone heat pump or air conditioner? For the age of another brand or manufacturer, go to our blog post How do I determine the age of my air conditioner? 

   To determine other key specs of your HVAC system, see one of these other blog posts: 

• How can I find out the SEER of my air conditioner?

• How can I tell whether the condenser (outdoor unit) is an air conditioner or heat pump? 

• How can I find out the size of my air conditioner? 

    To find the age of other home components, go to How can I find out the age of a roof? and How do I determine the age of an electrical panel? and How do I determine the age of my water heater? For life expectancies, visit What is the average life expectancy of the components of a house? 

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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: 

• My air conditioner won't turn on. What's wrong? 

• How can I find out the size of my air conditioner? 

• Where is the air filter for my central air conditioner and furnace? I can’t find it? 

• Does an old air conditioner use more electricity as it ages? 

• How did homes stay cool in Florida before air conditioning? 

• What is wrong with an air conditioner when the air flow out of the vents is low?

• Why has the thermostat screen gone blank? 

• Why does it take so long to cool a house when an air conditioner has been off for a while? 

• Why is my air conditioner not cooling enough? 

• What are the most common problems with wall/window air conditioners?  

• Will closing doors reduce my heating and cooling costs? 

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