Your standby generator has probably been sitting quietly since the last winter storm. It hums for a few minutes once a week, then goes back to sleep. That silence is easy to read as good news — but the only real test of a standby generator is the moment the grid drops on a 104-degree afternoon, and by then there is nothing left to check.
August is the right month to look at it. Central Texas asks more of backup power right now than at any other point in the year: peak heat, afternoon thunderstorms rolling off the Hill Country, and the outages that come with them. Here is what actually matters on a standby unit — what you can check yourself, and what needs a licensed electrician.
The weekly exercise cycle is a test, not maintenance
Most standby generators run a self-exercise once a week. That cycle proves the engine will start and run unloaded. It does not prove the unit can carry your air conditioner, and it does not replace oil, clean an air filter, or tell you the transfer switch will actually transfer.
Worth doing: stand outside during one cycle. Listen for a clean start with no extended cranking, a steady note once it settles, and no new rattle. If you have never heard yours run, you have no baseline — start there.
The battery is the most common reason a generator doesn’t start
A standby generator is a small engine with an electric starter, and that starter runs off a battery that spends its life in a metal box in the Texas heat. Heat shortens battery life. A unit that exercises perfectly all summer can still fail to crank on a battery near the end of its service life, because starting an engine under load asks far more of a battery than a no-load exercise does.
Check the terminals for corrosion and confirm the battery is within the replacement interval in your owner’s manual. If you cannot remember replacing it, that is your answer.
Oil, filters, and the schedule that came with your unit
Every manufacturer publishes a maintenance schedule based on run hours and calendar time, and the two clocks run independently — a generator that carried your home through several long outages has aged faster than the calendar suggests. Your controller tracks run hours; the manual tells you what those hours mean for oil, filters, and plugs.
One Texas-specific note: air filters load up faster here than the intervals assume. Caliche dust, cedar pollen, and grass clippings from mowing around the pad all end up in the intake.
Fuel is part of the system, not a detail
On natural gas, the generator is only as capable as the meter and gas line feeding it — and that line also serves your furnace and water heater. On propane, the question is simpler and easier to get wrong: how full is the tank right now? A generator sized for a three-day outage will run for exactly as long as the fuel lasts. Checking the tank level in August, before storm season peaks, costs nothing.
If your home has changed since the generator went in — a new pool heater, an added HVAC zone, a shop — the load calculation behind the original sizing has changed too. Our guide to sizing a standby generator walks through the method we use to check that.
Look inside the enclosure
Warm, dry, sheltered boxes are attractive real estate. Wasp nests in the intake, fire ant mounds at the base, and rodent damage to wiring are all things we find on units that were “running fine.” Open the enclosure per your manual, look for nesting material and chewed insulation, and clear vegetation back from every side. Airflow is not optional — a generator that can’t breathe overheats under load, which is precisely when you need it.
Don’t forget the transfer switch
The automatic transfer switch is the half of the system nobody thinks about. It senses the outage, disconnects you from the utility, and connects you to the generator. If it fails, a perfectly healthy generator sits there running while your house stays dark. It has contacts that wear and connections that loosen with thermal cycling, and it belongs on the same service schedule as the engine.
What a professional service adds
A proper annual service goes past the checklist above: a load test that proves the unit performs under real demand rather than at idle, controller diagnostics and stored fault codes, electrical connections torqued to spec, transfer switch inspection, and a fuel-pressure check under running load. That last one catches a problem no visual inspection will — a gas supply that reads fine at rest and sags the moment the engine asks for everything.
We’re Generac certified and support Kohler units, and we service generators regardless of who installed them. Ongoing coverage is available through our maintenance plans, or you can book a single visit.
When to call sooner
Don’t wait for the annual visit if you notice extended cranking before the engine catches, a controller alarm or warning light, a missed exercise cycle, visible oil under the unit, or a new noise. Any one of those is the unit telling you something while you still have the grid to fall back on.
Backup power is an investment in one specific outcome: the lights stay on when they otherwise wouldn’t. Maintenance is how that outcome stays true in year six, not just year one. If it has been more than a year since anyone opened your generator’s enclosure — or if you have never had it serviced — get a system health check scheduled before the next storm makes the decision for you.
Aether Energy is a licensed Central Texas electrical contractor (TECL #35881) serving Austin, Kyle, Buda, San Marcos, New Braunfels, and the surrounding Hill Country — solar service, battery storage, generators, EV charging, and residential electrical. When power matters. (210) 394-3961.
