What a yearly service includes
Generac's own yearly checklist for its home standby units has five items (Generac, Oct 2025):
- Check for water getting into the enclosure
- Inspect the battery
- Leak-test the fuel system
- Look for corrosion
- Change the oil and oil filter
A yellow maintenance light comes on once a year, counted from the day the unit was activated. It doesn't stop the generator from running in an outage. Generac's 20–26 kW parts kit also carries an air filter, pre-cleaner and spark plugs, so ask whether those get replaced too.
Oil change intervals by brand
| Brand | Oil and filter | Weekly self-test |
|---|---|---|
| Generac air-cooled | After the first 25 hours, then every 200 hours or 2 years; every 100 hours below 40°F or above 85°F | 5 minutes |
| Kohler (14/20RESA manual) | Yearly or every 150 hours | 90-second EcoExercise on the 26 kW |
| Briggs & Stratton | See the operator's manual for your model | 16 seconds |
From Generac, a Kohler 14/20RESA manual, the Kohler 26 kW spec sheet and the Briggs PowerProtect 17 kW spec sheet. Your own manual is final; intervals differ by model and year.
Why Baton Rouge heat shortens the interval
From May through September, the average daily high at Baton Rouge's airport is above 85°F, peaking at 92.2°F in August (NOAA 1991–2020 normals). Hurricane season falls in the same months. Under Generac's rule, that cuts the oil interval in half, to 100 hours.
Now put that against a real outage. Most of East Baton Rouge waited about 8 days for power after Ida in 2021 (WBRZ). Eight days is 192 hours of running, close to twice the hot-weather interval. Ask your dealer whether a mid-outage oil change is part of the plan, and keep the right oil and a filter at the house before June. More on how long outages last is in our outage history.
What it costs
| Item | Typical cost | Source |
|---|---|---|
| Yearly maintenance, whole-house unit | $200–600 | HomeAdvisor |
| Yearly maintenance, whole-house unit | $200–650 (portable: $50–150) | HomeGuide |
| Local owner, dealer plan | $500 a visit, twice a year | Tiger Droppings, 2026 |
| Generac 20–26 kW parts kit (filters, plugs; oil extra) | About $28–49 retail | Zoro |
| Battery | Replace about every 3–5 years | Generac |
The kit is cheap; the visit is mostly labor and travel. That's why plan prices vary so much. The cost guide folds a first-year plan into the installed price.
Can you do it yourself?
Generac says owners may do the routine tasks in their manual or hire a certified service dealer, but either way the maintenance records must be kept (Generac). Its Mobile Link app can log them. Changing oil is simple; leak-testing gas fittings and checking the transfer switch are jobs for the dealer. If you're under warranty, read what it requires first; our brand comparison sets out each maker's terms.
Questions to ask about a maintenance plan
- How many visits a year, and what's on the checklist for each?
- Is the oil change after a long outage included or extra?
- Do plan customers get priority calls after a named storm?
- Are the battery and spark plugs included or billed separately?
- Will the visit be logged with the manufacturer for warranty purposes?
Common questions
How often should a standby generator be serviced?
At least once a year. Generac also calls for an oil change after the first 25 hours of running, then every 200 hours or 2 years, or every 100 hours in heat above 85°F (Generac).
Do I need an oil change after a hurricane outage?
Often, yes. A week-long summer outage can run a unit past Generac's 100-hour hot-weather interval. Check the hour meter once power is back.
How long does a generator battery last?
Generac puts it at about 3 to 5 years, depending on use and conditions (Generac). It's checked at every yearly service.
Why does my generator run by itself every week?
That's the self-test. It keeps the engine lubricated and confirms it will start. Generac's runs 5 minutes, Kohler's EcoExercise 90 seconds, and Briggs' 16 seconds.
Sources & further reading
- Generac: yearly home standby maintenance (Oct 13, 2025). Tasks and oil intervals
- Generac: battery replacement. 3–5 years
- Kohler 14/20RESA operation manual. Service schedule
- Kohler 26 kW spec sheet. Exercise modes
- Briggs & Stratton PowerProtect 17 kW spec sheet. Exercise length
- HomeAdvisor: generator repair and maintenance cost. $200–600 a year
- HomeGuide: generator costs (2026). Maintenance by type
- Zoro: Generac 6485 maintenance kit. Retail price
- NOAA 1991–2020 monthly normals, Baton Rouge airport. Average daily highs
- WBRZ: eight days after Ida (Sept 2021)
- Tiger Droppings: Baton Rouge owner reports (2026)
Editorial note: General planning information, not engineering or legal advice. Prices are estimates; confirm current rules with your local officials and a qualified pro.