The following information pertains to grills made for the U.S. market. Some variations may exist for grills sold outside the U.S. and are noted below.
1985 to 1992
Weber did not code date information into the serial numbers of Genesis/Spirit grills made during these years. However, some owners report finding separate date stickers attached their grills, so you may want to look for that on early gassers.
The first-generation Genesis 1-5 grills had a serial number in this format:
_# 999999
_ was L for liquid propane or N for natural gas
# was the model number:
1 is the Genesis 1
3 is the Genesis 2
7 is the Genesis 3
4 is the Genesis 4
5 is the Genesis 5
999999 was the serialized number
The smaller Genesis XX, XXI, and Jr. models added an S before the L or N and were either S_1 999999 or S_2 999999, for example SL1 123456.
My 1991 Genesis 2 propane grill has a serial number L3 162105. L = propane, 3 = Genesis 2. The only reason I know it's a 1991 grill is because I remember the year I bought it! And don't be confused by the "1990" shown as part of the ANS designation. That's the gas safety standard to which the grill was built, not the year of manufacture.
1993
In 1993, Weber introduced the second-generation Genesis 1000-5000 grills. To differentiate these grills from earlier models, they added a K before the L or N and changed the model designations to 1/2/3/4/5 to match 1000-5000. So KL1 16527 is a Genesis 1000 LP grill; KL2 is a Genesis 2000 LP grill, etc. The Genesis 5500 (a built-in natural gas grill) used PMN instead of K as its designation for "Permanent Mount Natural Gas". The Spirit 500/700 used a P instead of a K.
Note: We have seen an example of a Genesis 5000 sold in Canada with serial number CL5 1844; L indicates propane, 5 indicates model 5000. We have also seen a Genesis 3000 sold in Canada with a serial number DL3 1525; L indicates propane, 3 indicates model 3000. We have even seen a Genesis 2000 sold in Norway with serial number EK2 1338...I assume that E represents Europe. So there can be variations in the old Genesis serial number scheme.
Here's an example of a 1993 Genesis 1000 with serial number KL1 18484:
1994
Starting in 1994, Weber introduced the two-letter AUTHORIZED date code and started using it on gas grills and owner's manual to indicated model year. See
How To Determine The Age Of Weber Grills & Smokers for info on Weber date code schemes for charcoal and gas grills.
We've seen examples as late as 1996 of dual-coded grills, for example this Genesis 2000 with both ER and KL2 codes:
View attachment 17085
Here's an example of a 1999 Genesis 2000 grill with serial number EE 151074:
More Recent Date Code Schemes
There are several more recent gas grill date code schemes you can read about in the
How To Determine The Age Of Weber Grills & Smokers article on The Virtual Weber Bullet website.
Thanks to TVWBB member
Dave Weaver for providing some of this Weber insider info on how to decipher old Weber gas grill serial numbers.