A standby generator is the one piece of home equipment that must work perfectly the moment it's needed most — and which most homeowners pay no attention to in the months and years between outages. Proper maintenance is not optional. Both Generac and Kohler void their 5-year warranties without documented annual service, and a neglected generator that fails during a major outage is worse than no generator at all. This checklist covers everything NoVA homeowners need to do — and when to do it.
Key Takeaways
- Northern Virginia's hot, humid summers accelerate battery degradation — test your generator's starting battery every spring and replace every 3–4 years.
- Weekly automatic exercises (10–15 minutes under load) are essential and should be programmed for a time that won't disturb neighbors.
- Annual professional service (oil change, filter replacement, spark plugs, load test) costs $200–$400 and is required to maintain warranty coverage.
- Check coolant and oil levels monthly — don't wait for the annual service if your generator exercises weekly and runs during outages.
- After any outage exceeding 24 hours, schedule a post-outage inspection to catch wear before the next event.
Weekly Maintenance: Your Generator's Automatic Exercise
Every modern standby generator should be programmed to exercise automatically once per week for 10–15 minutes. This brief run-under-load accomplishes several things: it lubricates engine components that would otherwise sit dry, charges the starting battery, keeps fuel flowing through lines and carburetors, and allows the control board to self-test all systems. Most Generac and Kohler units come programmed with a default weekly exercise schedule — confirm yours is actually running by checking the exercise log in the system's monitoring interface.
In Northern Virginia, program your exercise for Tuesday through Thursday, between 9 AM and 4 PM. This avoids weekend mornings (when neighbors are home and sleeping late), maximizes battery charging during daylight, and keeps your generator running during times when you could hear it start and confirm operation. A generator that exercises at 6 AM Sunday will generate noise complaints in any NoVA subdivision.
Confirm Your Exercise Is Running: Generac's Mobile Link app and Kohler's OnCue Plus both log each exercise event with runtime, load percentage, and any fault codes. If you haven't checked your monitoring app in 6 months, do it now. A generator with a failed exercise controller may not have actually run in weeks — and you'd have no way to know without checking the log. AJ Long Electric can review your system's exercise history during any service call.
Monthly Maintenance: Visual Inspection Tasks
Once a month, spend 5 minutes with your generator before or after your exercise day. Walk through this visual checklist:
Never lose power again. We are authorized Generac installers serving all of Northern Virginia. From sizing to installation to maintenance, we handle every step. Call (703) 997-0026 for a free in-home assessment.
Check for oil leaks around the engine block, oil pan, and drain plug — look for dark staining on the pad or concrete beneath the unit. Check the air filter housing for visible dirt, debris, or insect nests (yellow jackets and wasps love generator enclosures in NoVA summers — a nest inside can block cooling air and cause overheating). Inspect the enclosure for any physical damage, corrosion on the enclosure panels, or loose fasteners from vibration. Verify the gas line connections are tight and show no rust or moisture damage at the fitting points.
Check the battery terminals for corrosion — white or bluish-green powder at the terminals indicates oxidation that will eventually prevent the battery from starting the engine. A light coating of dielectric grease on the terminals after cleaning prevents this and is a 30-second task. Northern Virginia's humidity makes battery terminal corrosion more common here than in drier climates.
Monthly Oil and Coolant Check
If your generator exercises weekly and has been used during outages, check oil level monthly rather than waiting for annual service. Use the manufacturer-specified oil (typically 5W-30 synthetic for most Generac residential units) and don't overfill — fill to the full mark on the dipstick, not above it. Check coolant level in the overflow reservoir (on liquid-cooled units) and top off with the manufacturer-specified coolant type if below the minimum line.
Do Not Run Low on Oil: A generator engine running low on oil will trigger a low-oil shutdown — which means your generator turns off during an outage. In Northern Virginia's summer humidity, oil consumption can increase slightly in older engines. If you notice oil level dropping between annual service intervals, schedule a service call to investigate — it's an early indicator of ring wear that's far cheaper to address when caught early.
Spring Maintenance: Pre-Summer Storm Season Preparation
The most important maintenance window for Northern Virginia generators is March through April — before the spring storm season begins and the heat arrives. Northern Virginia's storm risk is concentrated in two periods: late spring/summer derecho season (May–September) and winter ice storm season (December–February). Spring maintenance prepares your system for the highest-probability outage period.
Spring tasks: Test the starting battery with a load tester (not just a voltage meter — a battery can show full voltage but fail under load). Replace the battery if it's 3+ years old regardless of test results. Inspect and clean the cooling system — flush debris from the air intake and cooling fins. Clear any vegetation that has grown toward the generator during the previous summer and fall (maintain the 18-inch clearance on all sides required for most installations). Test the automatic transfer switch function manually by simulating a power outage and confirming transfer within 10 seconds.
Annual Professional Service: What It Covers and What It Costs
Both Generac and Kohler explicitly require annual professional service to maintain warranty coverage. Annual service by a licensed, certified technician in Northern Virginia costs $200–$400 for a standard residential generator. Here's what that service includes — and what you should confirm is being done.
Oil and filter change: most residential generators specify oil changes every 200 hours or annually, whichever comes first. Given weekly exercise plus outage hours, most NoVA generators accumulate 50–80 hours of runtime per year — well under the 200-hour threshold, but annual changes are still required and prevent moisture contamination of oil that sits for long periods. Air filter replacement ($15–$45 in parts): a clogged air filter reduces engine power and can cause the generator to run rich, increasing carbon deposits. Spark plug replacement ($20–$60 in parts): every 2 years on most models, but inspect annually.
Load bank testing: a professional service should include running the generator at 50–80% of rated load for 30 minutes and monitoring voltage, frequency, and temperature. This identifies performance issues that don't appear during the weekly 10-minute exercise at light load. Any abnormal readings during load testing indicate maintenance needs before they become failure events. AJ Long Electric performs full load bank tests as part of every annual service in Northern Virginia.
Schedule Annual Service in September or October: The ideal time for annual generator service in Northern Virginia is September through October — after summer storm season but before winter outage season. This timing ensures your system is freshly serviced before the highest-risk winter period and avoids the spring rush when every homeowner suddenly remembers their generator needs attention after the first spring storm knocks out power. AJ Long Electric offers annual maintenance agreements that include a scheduled October service visit, priority scheduling during outages, and 15% off repair parts.
Post-Outage Inspection: After Any Extended Run
After any outage where your generator runs for more than 24 hours, schedule a post-outage inspection within 2 weeks. Extended runtime accelerates wear on belts, spark plugs, and filters. Check oil level and quality (extended runtime darkens oil faster). Inspect the exhaust system for carbon buildup. Reset the exercise schedule to ensure it wasn't disrupted by the outage event. Check battery charge and load-test it if the generator started multiple times during the event (rapid starting cycles are more demanding on the battery than continuous runtime).
After the extended 2021 ice storm outages in Northern Virginia, AJ Long Electric saw a wave of service calls for generators that had run for 72–96 hours and developed issues from deferred maintenance. Post-outage inspections are the maintenance step most homeowners skip and the one most likely to catch issues before the next event.
Multi-Year Maintenance Schedule
Beyond annual service, a few items follow multi-year intervals. Replace spark plugs every 2 years or 400 hours. Replace the air filter every 2 years (annually in dusty environments or near agricultural areas in western Loudoun). Replace the starting battery every 3–4 years — Northern Virginia's heat accelerates battery degradation compared to cooler climates. Replace coolant (liquid-cooled units) every 3 years. Inspect and exercise the automatic transfer switch contacts every 5 years; contact wear is the leading cause of transfer switch failures in older systems.
AJ Long Electric serves all of Northern Virginia — Fairfax County, Loudoun County, Arlington, Alexandria, Prince William County — for generator maintenance, annual service contracts, and emergency service. Call us at (703) 997-0026 to schedule your annual service or to set up a maintenance agreement that takes generator maintenance off your to-do list permanently. We maintain generators for both Generac and Kohler and stock common service parts locally to keep your system protected year-round.
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Written by
Matt Long
Master Electrician
Our team of licensed electricians brings over 40 years of combined experience serving Northern Virginia. We're committed to providing expert electrical solutions with a focus on safety, quality, and customer satisfaction.
Reviewed by AJ Long Electric Master Electricians · VA License #2705031092 · View Credentials
