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Title	How Do I Change the Oil and Oil Filter in a Generac Air-Cooled Home Standby Generator?

URL Name	How-Do-I-Change-the-Oil-and-Oil-Filter-in-a-Generac-Air-Cooled-Home-Standby-Generator

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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:

Maintenance Schedule:

Oil changes are listed as part of a generator's maintenance schedule. See the Where Can I Find the Maintenance Schedule for My Generac Home Standby Generator? article for more information.

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.

Oil Type and Filter Part Number

The correct oil type may vary based on the unit's run hours and temperature where the unit is installed. See the What Type of Oil Should I Use in My Home Backup Generator? for more information. Oil filter part numbers are listed in the user manual. See How do I find an oil filter for my home standby generator?

Maintenance Safety:

Owners should reference What Safety Precautions Should I Take When Performing Maintenance on My Generator? to ensure maintenance is performed in a safe manner.

Maintenance Kits:

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.

Consult the User Manual:

The process covered in this article applies to air-cooled Guardian (10-26 kW) series generators. Owners should always reference the user manual for maintenance tasks. See How Do I Find a Copy of My Home Standby Generator Owner's Manual and Spec Sheets? for more information.

Environment

This article applies to 10 kW - 26 kW Guardian series generators manufactured after 2017. Maintenance information for all generator models can be found in a generator's owner's manual. See the How Do I Find a Copy of My Home Standby Generator Owner's Manual, Spec Sheets, or Installation Manual? article for more information.

If the generator has been running in a power outage, refer to the "Shutting the Generator Off" section in How Do I Shut Down My Generator When It’s Powering My House (During an Outage)?

If the generator has not been running in a power outage, refer to the video, or proceed to step 1 of the written instructions below.

Video instructions

How to change the oil and oil filter on a Generac Home Standby Generator (written instructions):

If the generator has been running in an outage, refer to the "Shutting the Generator Off" section in How Do I Shut Down My Generator When It’s Powering My House (During an Outage)? Otherwise, proceed to step 1.

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 main line circuit breaker to off (If not running during a utility outage, skip to step 5).

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. Remove the cap and drain the oil into a suitable container.

Note: It is not uncommon to notice a milky sheen in used oil: What Would Cause My Generator Oil to Turn a Milky Color?

Oil Filter and Drain Location (10 kW):

Oil Filter and Drain Location (13–18 kW):

Oil Filter and Drain Location (20–26 kW):

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.

13. Remove the oil fill cap and fill the engine with the appropriate amount of oil: What is the oil capacity of a home standby generator?

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.

15. Press the manual button on the control panel to start the engine.

16. Run the generator for one minute and check for leaks.

17. Press the off button on the control panel to stop the engine and wait five minutes.

18. Inspect the oil level using the oil dipstick and a clean cloth.

19. If needed, add more oil, but do not overfill.

20. 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. Reinstall the 7.5-amp fuse.

2. Verify the generator's main line circuit breaker is still off and press the auto button.

3. Allow the generator to crank, start and run to warm up for one to two minutes.

4. Turn the Generator main line circuit breaker to the on position.

5. Turn the utility main line circuit breaker to the on position. The Generator is now fully operational and powering the load.

6. Be sure to dispose of the used oil and oil filter in accordance with national, state or local codes.