Some hvac brand also has new code for its new hvac units. For example, York hvac had two different serial numbers for 1971 through 2004 and for 2005 through the present day. You can’t use information from 2005 to decode 1980 hvac unit, it wouldn’t works. These air conditioner numbers mean a lot. Without the serial and model number, it would be hard to find a replacement part of that central ac unit (I’m not referring to small parts). You could say air conditioner serial and model number is it characteristics or it identities.
Re: Decoding older Rheem furnace Serial # - looking for manuf date Originally Posted by Scott Bennett Standing pilot gas furnaces such as the one pictured above were typically rated at 60% to 65% efficiency without a motorized vent damper and up to 70% with the motorized damper. Up near the top of the label, you see the model number (M/N) and serial number (S/N). The model number is where you can find the number you're looking for. Not all manufacturers do this, but most will give you a 2 or 3 digit section that tells you how many thousands of BTU/hour your air conditioner can move out of your home.
The Air Conditioner Serial and Model Number Tells Hvac model number tells you: Types of hvac unit, refrigerant types, hvac ton, voltage, compressor series, seer rating, and other thing. Hvac serial number tells you: Year, month, week, day, manufacturing plant location and sequential number.