Sears Boiler Age

Anyone have an age on this unit? Natural gas Sears Kenmore Boiler.

Serial # 2D512
Model # 229-96165

Thanks for any help.

Here is what I have. Does April 1951 seem right?

State/Reliance/Sears- Letter that equals the month followed by the year. (made by AO Smith)

Might be. Thanks.

I believe your D is the 1980s, with the 5 indicating 1985.

I knew you would have some info RR. Care to share with me how you cam eup with that?