How Often Should You Service a Standby Generator

A standby generator is the one piece of equipment you're counting on to work the moment everything else stops. That only happens if it's been serviced on a schedule — not just plugged in and forgotten between outages.

The baseline: once a year

Generac and every other major manufacturer specify annual maintenance for home standby units, or every 100–200 hours of run time, whichever comes first. That interval assumes normal residential use: periodic self-test cycles, a handful of real outages a year, and moderate conditions.

Skipping the annual service doesn't just risk a no-start during the next outage — on units still under factory warranty, it can also void coverage if a failure traces back to deferred maintenance.

What pushes the interval shorter

In Teller County and the rest of the high country, a few local factors mean "once a year" is a floor, not a target:

• Altitude. Air-cooled engines running at 8,000–10,000+ feet work harder for the same output. Carburetion and air filtration need checking more often than the manual's sea-level assumptions account for.
• Dust and wood smoke. Unpaved roads and wildfire-season smoke load air filters faster than a typical suburban install.
• Heavy outage use. If your unit ran for days during a real grid outage rather than just its weekly exercise cycle, treat that as extra hours toward the 100–200 hour mark — a generator that just carried your house for 72 hours needs a look before its next scheduled visit, not after.
• Propane vs. natural gas. LP units see more carburetor and regulator issues over time and often benefit from a mid-year check in addition to the annual service.

If two or more of these apply to your setup, we generally recommend moving to a twice-a-year interval — spring, before storm season, and fall, before heavy heating-season demand on the electrical system.

What an actual service visit covers

A real annual service is more than an oil change. On a Generac home standby, ours includes:

1. Oil and oil filter change (synthetic, per Generac spec)
2. Air filter inspection and replacement
3. Spark plug inspection and gap check
4. Battery load test and terminal cleaning
5. Fuel system inspection — regulator, valve, and connections
6. Automatic transfer switch exercise and contact inspection
7. Evolution/Nexus controller fault code review
8. A load-bank or real-load test to confirm the unit actually carries the house, not just starts

That last step matters most. A generator that starts and runs unloaded can still fail the moment it's asked to carry a refrigerator, well pump, and furnace blower at once — the only way to know is to test it under load.

Signs you need service before your next scheduled visit

Don't wait out the calendar if you notice:

• A weekly self-test that ends in a fault code instead of a clean shutdown
• Visible smoke, an oil smell, or a fuel smell during the self-test
• A cranking sound that takes longer than usual before it catches
• The Mobile Link app reporting a fault or a missed exercise cycle

Any of these means the unit should be looked at now, regardless of when it was last serviced.

Keeping it simple

If you'd rather not track hours and dates yourself, our maintenance plans put your generator on an automatic annual (or semi-annual, for higher-use setups) schedule — we track the interval, reach out to book the visit, and keep the paperwork your warranty depends on. As a Certified Generac Service Dealer, we use genuine parts and file the work the way Generac expects, so your coverage stays intact.

Get a generator maintenance quote or call (719) 362-0701 to get on the schedule.