Furnace
M# DGAA056BDTA
S# W0A5380672
Compressor
M# S3QA-036KA
S# S3A050402394
Mobile home built in '05.
'05 seems reasonable, just would like to understand the coding here. Doesn’t seem to fit with the common YY format (at least with the furnace).
TIA
**Coleman: **Serial numbers prior to April 1992=1st two numbers are month, then year, then series.
After April 1992, 1st two numbers are year, then month, then series.
Thanks, Brian - I have that, but the S# is a bit confusing
the first two #s are indeed 0-5, but separated by an “A”. Should I disregard the “A” or does the “A” make 5-3 the first two numbers? It certainly is not 1953. 
If I disregard the “A” that makes it the 38th month of '05. If 53 are "the first two numbers, then it is the 80th month of 53 (or the 53rd month of '80). :shock:
And yes, the S# is correct, I checked it 5 times.