Generac Generator Service Schedule: How Often to Maintain for Reliable Backup Power

Homeowners in Charlotte buy a generator for one reason: when the grid drops, life goes on. Lights stay on, the fridge keeps cold, and the AC keeps breathing through a Carolina heatwave. That only happens if maintenance is consistent and smart. The right schedule is not generic; it depends on your Generac model, your fuel type, local weather, and actual run hours. This is https://ewingelectricco.com/generac-generator-services/ the maintenance timeline we recommend as a Generac authorized service provider serving Charlotte, NC and nearby neighborhoods like SouthPark, Ballantyne, Steele Creek, Huntersville, and Matthews. It is grounded in factory guidance, field experience, and what we see during storm season here.

The short answer first

Most residential Generac standby generators should receive a professional service every 12 months or at 100–150 run hours, whichever comes first. If your generator runs hard during hurricane season or extended outages, schedule service as soon as you cross the run-hour threshold, even if the calendar says you are early. Between annual visits, you handle a few simple checks: keep the area clear, clear the snow or leaves, glance at the control panel after weekly exercise, and change the air filter or spark plugs if a message or a performance change calls for it.

Those basics cover most homes. Now, here is a practical timeline with specifics for Charlotte’s climate, followed by details on what each visit includes, what actually fails in the field, and when it is smarter to call for Generac authorized service rather than trying a DIY fix.

How Charlotte’s climate changes your schedule

Humidity, pollen, and heat load matter for a generator. In Mecklenburg County and surrounding areas, our heat index runs high from May through September. Air filters load up faster with pollen in spring. Summer heat thins oil and stresses batteries. Fall storms can run a generator for long stretches, then winter cold reduces cranking amps. That is why a once-per-year service is the floor, not the ceiling, for reliability.

If your generator sits near pine trees or a mulched bed, plan on an air filter check mid-season. If your unit backs up a critical load like a sump pump or medical equipment, treat oil and filter service by run hours, not by date. We see the most nuisance shutdowns after long runs in August and after the first deep cold snap in January. Both events are predictable and preventable with the right prep.

A practical maintenance timeline for Generac standby units

Most Generac home standby generators complete a weekly exercise cycle. Many models default to 5 to 12 minutes per week. That self-test is useful, but it is not a maintenance program. Here is how we structure service for a typical 14–26 kW Generac running on natural gas or propane in the Charlotte area.

Weekly at a glance: Let the exercise run. Walk past the unit. Listen for an even idle during the test. Look at the control panel: any yellow or red status needs attention. Confirm the area is clear of leaves, nests, and lawn clippings. If you smell gas, shut the unit down and call for service.

Monthly: Open the lid and check the air filter for heavy debris. Wipe off dust. Check oil level with the dipstick while the unit is cool. On propane systems, check the tank gauge; if it is under 30 percent, schedule a fill and test the regulator for frosting or odor.

Every 6 months or 75 run hours: If you had heavy spring pollen, a long outage, or construction dust nearby, replace the air filter and inspect spark plugs. Check battery terminals for corrosion and clean them. Confirm that your utility load-shed modules, transfer switch, and Wi-Fi monitoring still report correctly.

Annually or at 100–150 run hours: Book Generac authorized service. This visit includes oil and oil filter, air filter, spark plugs, valve clearance check for many models, battery test under load, firmware updates if applicable, full controller diagnostics, exhaust and fuel system inspection, and a transfer switch check. For units that experienced long outages, we prefer the 100-hour mark over a date on the calendar.

Every 2–3 years: Replace the battery. Eighty percent of no-start calls we field on cold mornings trace back to weak batteries that passed a quick voltage check but failed under load. We replace instead of waiting for the first hard failure.

Every 5 years: Inspect fuel regulators and flexible gas connectors, test gas pressure during load, replace aging gaskets, and re-check grounding and bonding. PVC conduits and rubber components age faster under sun exposure; replacements prevent leaks and nuisance faults.

This schedule keeps most Charlotte units in ready condition, while giving extra attention before the two stress windows: late summer heat and mid-winter cold.

What a proper annual service includes

Oil and filter change: Generac engines are small displacement, high RPM, and air cooled. They shear oil faster than automotive engines. We use the viscosity grade specified on the model tag, typically 5W-30 synthetic for our region, and verify the change interval by run hours. Thickened or fuel-diluted oil is a red flag; it often points to rich burn, stuck choke, or short-run cycles in cold weather.

Air filter and spark plug service: In Charlotte, spring pollen loads filters early. A gray or lightly dusted filter can wait; a dark, matted element should be replaced. Spark plugs foul faster on propane when the mixture is off. We gap to spec and log the result. If we see a repeated soot pattern, we adjust and re-test.

Valve clearance: Many Generac models specify periodic valve lash checks. This is not optional. Tight valves reduce compression when hot and cause intermittent shutdowns after long runs. The symptom looks like a fuel problem to a homeowner, but it is mechanical. We check hot and cold values as the model calls for.

Battery test: We load-test, not just measure voltage. The small starting batteries on residential units can show 12.6 volts at rest and still sag under crank. A failing battery causes long crank cycles and controller faults that mimic other issues. We also check the charger output and the parasitic draw.

Controller diagnostics and firmware: Most newer Generac units track run hours, faults, and exercise logs. We scan the history, clear nuisance codes after fixing the cause, and update firmware when releases address known issues. We confirm network communications for Mobile Link monitoring if installed.

Fuel and exhaust inspection: On natural gas, we confirm pressure at the generator with the unit under load. On propane, we check regulator performance and look for frost or odor during operation. Exhaust leaks are a safety issue; gaskets and joints must be tight, especially near windows and soffits.

Transfer switch inspection: The generator is only half the system. We inspect the ATS contacts, torque critical lugs, check utility sense operation, and test transfer and re-transfer under supervised conditions. Loose lugs cause heat, which leads to premature failure.

A thorough annual visit typically takes 60–120 minutes, depending on access and findings. Most of the value is in the testing and measurements, not just changing oil.

Run hours, not just calendar dates

We see homeowners surprised by the 100–150 hour guidance, because the machine might look clean and new. Here is why hours matter. During an extended outage, your generator can rack up 24 hours a day. Four days of runtime equals a year of light duty. Oil additives deplete, air filters load, spark plugs erode, and valves drift. If you hit 100 hours in August after a storm, call for service then. Waiting for your annual winter slot can put the engine at risk of low oil pressure shutdown or plug fouling during the next event.

The reverse is true for low-use homes. If you barely rack up 20 hours a year, oil still ages with heat cycles and moisture. Annual service is still smart, but we will set the interval by the calendar rather than hours.

Differences by fuel type: natural gas vs propane

Both fuels burn clean compared to gasoline, but they have quirks.

Natural gas: Supply is steady, but pressure can sag during high demand. We test pressure at the unit while it is running to catch a weak regulator or undersized pipe. If your generator shares a line with a pool heater or large range, we size the piping to handle concurrent loads. Undersupply causes lean burn, backfires, and low frequency alarms.

Propane: BTU content is stable, but regulators age. Frost on the regulator during a long run can be normal at certain loads, but it should not starve the engine. In cold snaps, small tanks can have vaporization limits. We recommend tank sizing that matches your kW rating and expected runtime. A 10–13 kW unit can run 24 hours on about 100–150 gallons depending on load, so a 250-gallon tank gives you margin during delivery delays.

Service intervals are similar, but propane systems need a closer eye on the regulator and fuel piping, and natural gas systems need a verified under-load pressure test during the annual visit.

What homeowners can do between professional visits

You do not need to wrench on your generator every weekend. A few habits prevent 80 percent of nuisance calls.

• Keep 3 feet of clear space around the unit. Trim shrubs, blow out leaves, and stop mulch from drifting up against the housing.
• Check the control panel after the weekly exercise. Green light means normal. Yellow is a warning. Red is a shutdown. Do not ignore a warning for weeks.
• Glance at the oil level monthly when the engine is cool. Top up only with the correct oil type and do not overfill.
• For propane units, check the tank level after long runs and before the first cold snap. Call your supplier at or before 30 percent.
• Keep the lid seals clean. Dirt in the gasket lets water into the enclosure and corrodes connectors.

These five steps take minutes and save you from discovering a fault in the dark during a storm.

Common failure points we see in Charlotte

Battery neglect: A battery lasts 2–3 years in our heat. Many fail at year three without warning. Replace on schedule, not after a no-start.

Clogged air filters after landscaping: Leaf blowers pack debris into the intake. We find filters that look like felt blankets after a single yard cleanup. If you mow, glance at the filter that day.

Loose gas fittings after utility work: After a meter swap or piping change, small leaks show up at the generator union. A sniff test and a bubble test catch it. If you smell gas, close the manual gas valve and call for service.

Aging regulators on propane: Five-year-old regulators often start to drift. Symptoms include surging, hunting idle, or shutdown under load.

Valve lash out of spec: Generators that run hard during outages often come due for a valve adjustment ahead of schedule. Hot restarts fail, then clear after a cool-down. That is the tell.

These are why we emphasize Generac authorized service. Training and parts availability matter when you are trying to fix a shutdown under load instead of swapping parts at random.

How the weekly exercise helps and what it does not tell you

The exercise proves the engine starts and runs. It does not prove the generator will carry load for hours. It does not check under-load gas pressure or battery performance during a hot restart. If the exercise sounds rough, stalls, or produces a new smell or vibration, that is a signal to schedule service before the next storm window. We can run a load test, verify voltage and frequency under load, and correct fuel or ignition issues before they turn into a shutdown at 2 a.m.

Warranty and Generac authorized service

Keeping your maintenance in line with Generac’s schedule protects your warranty and protects your investment. As a Generac authorized service provider, Ewing Electric Co uses factory procedures, software, and parts. We log run hours, save controller history, and note service dates that support warranty claims for covered failures. Non-authorized work with non-OEM parts can create disputes that delay repairs. More importantly, our technicians see, in person, what fails on Charlotte installations. We bring that experience to your yard.

The value of a maintenance plan

Many homeowners prefer a set-it-and-forget-it approach. A maintenance plan locks in the right cadence and reduces the chance you call us only after a failure. Our Charlotte plans include one annual service with oil, filters, plugs, a load-bank or live-load test when appropriate, and priority scheduling during storm season. We schedule around pollen spikes in spring and before the Atlantic hurricane peak. That timing is not arbitrary; it matches when generators are most likely to be stressed here.

If you own a short-term rental or a property with critical loads, we can move you to a semi-annual plan. For most houses, the annual plan plus the run-hour trigger covers it.

Edge cases: low-use homes, high-use homes, and special loads

Low-use, infrequent outages: The generator runs a 12-minute exercise and almost nothing else. Annual service still matters because oil ages and batteries sit. We may adjust the exercise schedule to a lower RPM quiet test if the neighborhood has noise sensitivity. We still recommend a load test every year to prove the system will transfer.

High-use homes with repeated outages: Use the hour meter as your guide. Oil and filter at 100 hours, even if that is twice a year. Keep spare air filters on hand. We can teach you how to swap a filter and check plugs between visits.

Homes with medical or mission-critical equipment: Consider a redundant UPS for the equipment, even with a generator. We test transfer times and frequency stability under load. We also recommend Wi-Fi monitoring for real-time alerts.

Propane-only homes with small tanks: Upgrade the tank or add a second tank if your runtime requirement is more than a day at typical load. Vaporization limits are physics, not preference. A larger tank also stabilizes regulator performance in cold weather.

Coastal or lakeside properties: Corrosion loads rise with salt and moisture. We add dielectric grease to key connectors and increase inspection frequency for enclosure corrosion and exhaust components.

Signs you should schedule service now, not later

Your generator should start cleanly, settle into a steady idle, and transfer power without drama. If it does anything else, do not wait.

• Longer than normal crank time or multiple start attempts
• Hunting idle, surging, or visible exhaust smoke
• Fuel smell near the unit or regulator frost that worsens during short runs
• Frequent exercise failures or new warning lights after weeks of normal behavior
• Breaker trips or dimming lights when the generator takes load

Any of these justify a service visit. They are often early warnings that save you from a hard shutdown during an outage.

Why professional service beats DIY for most owners

There is room for homeowner checks, but a full service needs the right parts, tools, and measurements. Valve lash requires feeler gauges and model-specific specs. Load testing requires safe setup and observation. Gas pressure must be checked under load, not at static. Controller updates need the correct interface. The biggest difference is judgment. A Generac authorized service tech can tell you whether the spark plug color points to a simple mixture tweak or a deeper valve issue. That judgment saves you time and avoids repeat failures.

If you enjoy working on engines, we are happy to support you with parts and guidance for light items. For core service, let us handle it and document it for your records.

Cost ranges and what drives them

For a typical 14–26 kW Generac in Charlotte, an annual service visit with oil, oil filter, air filter, spark plugs, diagnostics, and transfer switch inspection generally runs in the low-to-mid hundreds, depending on model and access. Load-bank testing, valve adjustments, and parts beyond consumables can add to that. Batteries typically add another modest line item every 2–3 years. If a regulator, control board, or transfer switch component needs replacement, parts can range higher. We quote before work and keep old parts available for review.

The cost of service is measurable. The cost of a failure during a 98-degree day with a full fridge and kids at home is also measurable. Most of our clients look at that trade and choose a plan.

What to expect during an Ewing Electric Co visit

You will get a set arrival window, a text when we are on the way, and a clear work sequence on site. We photograph key readings, note serial numbers and firmware versions, and record torque values on critical electrical lugs. At the end, we run the generator under live load where possible, verify voltage and frequency, and confirm the home is back on utility power. We leave the site clean. You get a digital report with run hours, findings, and a suggested interval for the next visit based on your actual usage.

Service coverage across Charlotte

We service Charlotte proper and nearby communities including Ballantyne, Dilworth, Plaza Midwood, South End, Myers Park, Steele Creek, University City, Huntersville, Cornelius, Davidson, Matthews, Mint Hill, Indian Trail, Fort Mill, and Pineville. If you are outside these areas, call us and we will confirm availability or refer you.

Ready to set your schedule?

If your Generac has crossed 100 run hours this year, or if it has been 12 months since your last service, you are due. If you saw a yellow or red light after the last exercise, schedule now. As a local Generac authorized service provider, Ewing Electric Co can get you on a smart timeline that fits Charlotte’s climate and your real usage. Call, text, or book online. We will keep your generator ready so you do not think about it again until the lights flicker and the system does exactly what you bought it for.