Maintenance & Exercise Cycle
Standby Generator Maintenance Schedule and Weekly Exercise: What Owners Need to Know
The service intervals that keep a standby generator reliable — and keep its warranty intact — plus what that weekly self-start you hear is actually doing.
Why Maintenance Matters
This isn't just about longevity. Generac states that performing oil service per the owner's manual is required “to maintain product warranty.” Skipping documented maintenance can affect your coverage — which is exactly why warranty fine print and a service log belong in the same conversation. (See how warranty coverage tapers in our Generac vs. Kohler comparison.)
The timing is what makes this matter. On both Generac and Kohler, the standard 5-year limited warranty covers labor only in years 1–2; years 3–5 are parts-only on major engine and alternator components. A documented service history is exactly what protects you in those later years, when a labor bill is already on you.
Generac Service Schedule
Generac's documented intervals for its air-cooled standby line:
| Interval | What to do |
|---|---|
| Before each use | Check oil; inspect for leaks and check the louvers. |
| Annually | Fuel-system leak test; water-intrusion check. |
| Every 2 years / 200 hours | Battery check; oil and filter change. |
| Every 4 years / 400 hours | Air filter; spark plugs. |
| Break-in (at 25 hours) | Initial oil change. |
Cold-climate (and high-heat) note
When the generator operates below 40°F — or sustained above 85°F — Generac shortens the oil-and-filter interval to every 1 year / 100 hours. That matters in cold-winter climates, where a standby unit may run for long stretches in deep cold during an outage.
Maintenance-kit part numbers aren't published in the owner's manual — your dealer supplies the correct kit for your specific model, so we don't list part numbers here.
The Weekly Exercise Cycle
That brief self-start you hear on a set day each week is normal — it's the exercise cycle keeping the engine lubricated and ready. On a Generac it self-starts on a configurable schedule, factory-set to 5 minutes (older units and the PowerPact run 12 minutes). The Quiet-Test feature on 10–26kW models runs the exercise more quietly. The cycle only runs when the generator is set to AUTO.
A Kohler with the RDC2 controller runs an unloaded exercise for 20 minutes, weekly or biweekly. Either way: the weekly run you hear is a routine self-test, not a problem.
Kohler Service Schedule
The documented intervals for Kohler's air-cooled RCA line, from Rehlko/Kohler service document TP-7092. Where the 26RCA running premium oil differs from the standard interval, we show both rather than resolve to one.
| Item | Interval |
|---|---|
| Oil change | Yearly / 150 hours (standard). 26RCA on premium oil: every 2 years / 300 hours. |
| Oil filter | At each oil change. |
| Air cleaner | Check at 150 hours; change at 300 hours. |
| Spark plugs | Check at 150 hours; change at 300 hours. |
| Battery | Check monthly; service the terminals yearly. |
Source: Rehlko/Kohler doc TP-7092. Kohler is now the Rehlko brand; these generators are still sold as “Kohler.” The 26RCA's longer 2-year / 300-hour oil interval applies only when the unit is filled with the specified premium oil — confirm the oil type and interval for your model with your dealer.
Keep going
Seeing a warning light or a unit that won't start? Our troubleshooting & status-light guide decodes the alarms. Still shopping? Compare brands in the Generac vs. Kohler comparison, and see what an install runs in the cost guide. Planning the install itself? The permits & utility guide covers fees, setbacks, and inspections.
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