Read the manual thoroughly and understand all of the instructions, cautions, and warnings before using this equipment. If any section of the manual is not understood, contact your nearest authorized dealer, or contact Generac Customer Service at 1-888-436-3722 (1-888-GENERAC), or www.generac.com with any questions or concerns.
Changing the Oil and Oil Filter
Generator owners should reference these articles before changing the oil:
If the generator is running for extended periods during an outage (continuous use), then it should be shut down every 24 hours to check oil levels. See Continuous use maintenance for home standby generators for more information.
Generac sells maintenance kits that bundle OEM parts for maintenance tasks. See the What Are Generator Maintenance Kits? article for more information.
Authorized Service Dealers:
While generator owners can certainly perform maintenance tasks, scheduled maintenance tasks can also be completed by a certified service dealer. See the How Can I Find a Generac Service Dealer in My Area? article for more information.
1. Lift the generator's lid and press the MANUAL button on the control panel to start the engine.
2. Let it run for 3-5 minutes or until the engine is thoroughly warmed up.
3. If running during a utility outage, set generator's the generator's main line circuit breaker to OFF (If not running during a utility outage, skip to step 6).
4. Set the utility main line circuit breaker to OFF.
5. Allow the generator to run and cool down for five minutes with no load applied.
6. Then, press the OFF button on the control panel to shut down the engine.
7. Allow the generator to cool for another five minutes before working on it.
8. Remove the front panel when the unit has cooled. Pull oil drain hose (A) free of retaining clip. Prepare a suitable container to drain the oil into, remove cap from oil drain hose and drain oil.
9. After all the oil has been drained, reinstall the cap onto the oil drain hose and secure the hose to the retaining clip.
10. Remove the oil filter by turning it counterclockwise.
11. Screw the new filter on by hand until the gasket lightly contacts the oil filter adapter.
12. Then, tighten the filter an additional three quarters to one full turn. Confirm it is tight and secure.
13. Remove the oil fill cap and fill the engine with the recommended amount of oil, referencing the table below:
Guardian Series Power Rating
10 kW
14/18 kW
20–26 kW
Oil capacity including filter
Approx. 1.1 qt (1.03 L)
Approx. 2.2 qt (2.1 L)
Approx. 1.9 qt (1.8 L)
Oil fill location (10 kW)
Oil fill location (14 kW - 18 kW)
Oil fill location (20 kW - 26 kW)
14. Once the appropriate amount of oil has been added, secure the oil fill cap and press the MANUAL button on the control panel to start the engine.
15. Run the generator for one minute and check for leaks.
16. Press the OFF button on the control panel to stop the engine and wait five minutes.
17. Inspect the oil level using the oil dipstick and a clean cloth.
18. If needed, add more oil as needed. DO NOT OVERFILL.
19. Insert oil dipstick and/or attach fill cap.
20. Replace the front panel.
21. If the generator was not running due to a utility outage, simply press the AUTO button and close the lid. Be sure to dispose of the used oil and oil filter in accordance with national, state or local codes.
If the generator has been running because of an outage:
1. Unlock and lift lid and press the MANUAL button on control panel to start engine. Run unit for 3-5 minutes or until it is thoroughly warmed up. Press OFF button on control panel to shut down engine.
2. Remove front panel when unit has cooled. Pull the blue oil drain hose free of retaining clip. Prepare a suitable container to drain the oil into, remove cap from oil drain hose and drain oil.
3. Install the cap back on the oil drain hose. Position and secure oil drain hose with the retaining clip.
4. Remove oil filter by turning it counter-clockwise.
5. Apply a light coating of clean engine oil to the gasket of the new filter.
6. Screw new filter on by hand until gasket lightly contacts oil filter adapter. Then, tighten the oil filter an additional three-quarters to one full turn. Confirm it is tight and secure.
7. Fill the engine with the recommended amount of oil, referencing the table below:
Next Generation Series Power Rating
10 kW
14/18 kW
22–28 kW
Oil capacity including filter
Approx. 1.4 qt (1.3 L)
Approx. 2.5 qt (2.4 L)
Approx. 2.2 qt (2.1 L)
8. Press the MANUAL button on control panel to start engine. Run for one minute and inspect for leaks.
9. Press the OFF button on control panel to stop engine. Wait five minutes.
10. Inspect oil level. Add oil as needed. DO NOT OVERFILL.
11. Insert oil dipstick and/or attach fill cap.
12. Replace the front panel.
13.Press AUTO button on control panel.
14.Close and lock lid.
15.Dispose of used oil and filter according to local, state, or national codes.
If the generator has been running because of an outage:
