What year is it? M/N 3115-A751

[melisa.miller]

I am trying to find out the year on a Coleman Central Furnace. The model number is 3115-A751 and the serial number is 057762288. Any help is greatly appreciated. Thanks!

[Mark]

The first 4 numbers of the serial number is the date code. In some furnaces, its the first three numbers as the zero is sometimes dropped. A serial number should be 9 digits. If its only 8, add a zero to the front.

Anyway, your furnace was manufactured in May of 1977.

Mark