Kohler Serial & Model Number Guide
Every Kohler generator carries a model/serial label. Here is where to find it, what each part of the number means, and how to use it for parts, service and age.
Break down your Kohler number
Paste your model / spec number (e.g. 20RCAL) and we'll label each part. Best-effort — always confirm against your data plate.
What the number means
Worked example — 20RCAL:
| Part | Meaning | Detail |
|---|---|---|
20 | Rated power (kW, LP) | kW standby rating on LP/propane; the natural-gas rating is typically lower (e.g. 20RCA = 20 kW LP / 18 kW NG). |
R | Series letter | Leading letter of the series name — not a reliable per-letter code (R appears on residential RES/RCA and on industrial REOZK/REZG alike). |
CA | Model series | The air-cooled residential / light-commercial series (RES → RESA → RCA). |
L | ATS suffix | A trailing L = shipped with a Kohler RXT automatic transfer switch (RCAL / RESAL); no L = supplied without the ATS. |
Using the serial number
Record the Model Designation, Specification Number and Serial Number from the nameplate. The model gives the rating and series; the serial ties to the individual unit. Kohler home-standby generators have no public serial→year formula — find the age via Kohler or a dealer. (The “add 70 to the first two serial digits” trick is for Kohler small ENGINES, not generators — don't apply it here.)
Common Kohler maintenance parts
The service parts Kohler's own documents list across more than one generator model. Confirm the number for your unit on its model page or data plate before ordering.
| Part | Part number | Fits | Price |
|---|---|---|---|
| Oil filter | GM32809 | 9 Kohler models incl. 100REOZJ, 100REOZJE, 125REOZJG | eBay $26.25 NAPA $28.76 Amazon |
| Oil filter | 230510001 | 9 Kohler models incl. KD1000-UE_380, KD1250-4, KD1250-E | eBay $40.80 NAPA $117.18 Amazon |
| Fuel filter | GM50006 | 6 Kohler models incl. 100REOZJE, 125REOZJG, 150REOZJF | eBay $26.99 NAPA $44.17 Amazon |
| Fuel filter | GM50074 | 5 Kohler models incl. 125REOZJG, 150REOZJF, 180REOZJG | NAPA $38.35 eBay $70.33 Amazon |
| Air filter | 002175339000 | 4 Kohler models incl. 30REOZJ, 40 REOZK4, 40REOZJ | eBay $40.50 |
| Air filter | 10801001001 | 3 Kohler models incl. KD1250-E, KD1250-KD1750, KD1600 | NAPA $242.77 Amazon |
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Popular Kohler models
Full specs, parts and maintenance data for specific units:
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Decode rules verified against: Kohler spec sheet TP-7092/7094 + Kohler Assist model/serial guide. Figures are for reference; confirm against the official documentation for your exact unit.