The Kohler 12RESV produces 12kW on propane and 11kW on natural gas. It uses a KT725, 725cc V-twin engine running at 3,600 rpm, with 20.3kVA of peak motor-starting capability.
The Kohler 12RESV is intended for a compact essential-load installation needing more output and starting headroom than the 10RESV.
Kohler 12RESV questions answered: sizing, cost, fuel and maintenance
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Kohler 12RESV Specifications (Manufacturer Data)
| Specification | Kohler 12RESV | Source |
|---|---|---|
| Rated output, natural gas | 11 kW | 1, 2 |
| Rated output, propane (LP) | 12 kW | 1, 2 |
| Engine | Kohler KT725, 725 cc, air-cooled | 1 |
| Dimensions (L × W × H) | 30.6 × 28 × 32.4 in (777 × 712 × 824 mm) | 1 |
| Weight | 433 lb (196 kg) shipping weight, generator set | 1 |
| Sound level | 67 dB(A) weekly exercise; 71 dB(A) full-speed operation (8-point logarithmic average at 7 m / 23 ft, no load; lowest point 64 / 69 dB(A)) | 1 |
| Natural gas use, ½ load / full load | 128 / 216 ft³/hr | 1 |
| Propane use, ½ load / full load | 57 / 103 ft³/hr | 1 |
| Line circuit breaker | 60 A | 1 |
| Transfer switch options | Optional Kohler Model RXT or RDT automatic transfer switch, with load-shed kit and power relay modules available; 12RESVL package adds a 100 A RXT with 12-space load center | 1 |
| Warranty | Premium 5-year/2,000-hour limited standby warranty (parts, labor and travel); 7-year and 10-year limited warranties optional | 1, 2 |
| Starting MSRP (Kohler product page) | $4,384 | 2 |
What the size and fuel figures mean for installation
Kohler says the 12RESV can be placed as close as 18 inches from a home, citing NFPA guidance for clearance to combustible materials, and tells buyers to check state and local codes; the sheet also offers 3 in and 4 in concrete mounting pads and notes its dimensions are for reference, not installation planning. On propane, 57 ft³/hr at half load converts to about 1.57 gal/hr using Kohler's own factor of 36.39 ft³ per gallon, or roughly 113 gallons over a 72-hour outage (our arithmetic). See the propane tank sizing guide. (Source: 1.)
Specification sources, checked October 3, 2026:
Where the 12RESV Fits
The Kohler 12RESV is intended for a compact essential-load installation needing more output and starting headroom than the 10RESV. On natural gas, plan against 11kW rather than the propane nameplate. The 20.3kVA starting rating describes a short motor-start event and cannot be added to the running output.
Inventory the loads you need during an outage, including HVAC starting current, pumps and electric heat. Use the generator size calculator to organize the load list, then have an installer check the design against the exact alternator and fuel configuration.
Equipment Cost and Installation Scope
Kohler’s starting equipment MSRP for the 12RESV is $4,384, checked September 30, 2026. That is not an installed price.
A complete quote should itemize the generator, compatible transfer switch, battery, foundation, electrical and fuel work, permits, commissioning, registration and any load controls or cold-weather accessories. Long trenching runs, gas-meter upgrades and changes to service panels can materially change the total. Compare equivalent scopes from local installers; no national installed average is asserted here.
Source: Kohler 12RESV consumer catalog.
Transfer Switch and Fuel Supply
Confirm the exact package: 12RESV and 12RESVL are different purchasing choices. The L package is the transfer-switch bundle; do not assume a base-model equipment quote includes the switch. Require the transfer-switch model, amperage, service-entrance rating and load-management accessories as separate named items in the quote. The consumer catalog’s “Included” field can conflict with the technical-sheet options or its package FAQ. Written SKU-level confirmation is the reliable purchasing check. A generator’s kW rating alone does not determine the correct transfer switch.
Source: Kohler 12RESV technical specification.
At full load, the technical sheet lists 216 ft³/hr of natural gas and 103 ft³/hr of LP vapor. Have the installer check fuel supply with the other connected appliances operating; a meter label or short pipe run alone does not establish sufficient capacity.
Ownership and Service
The April 2026 TP-6880 schedule calls for oil and filter service yearly or at 100 operating hours, whichever comes first. Check oil every eight operating hours or before use; valve-lash service is listed at 500 hours. Use the complete current manual for air-filter, ignition, battery and other service tasks. Severe conditions may require shorter intervals; match the manual to your model and serial number.
Source: Kohler 12RESV operation manual.
Compare the Kohler Line
Compare running output on your actual fuel, peak motor starting, cooling architecture and installed system cost. Local commissioning, parts access and service response are material parts of the purchase.