You bought a whole-house generator so the fridge, sump pump, and a few circuits stay alive when the utility fails. The part most owners skip is the boring maintenance between outages. Generac Schedule A is that boring maintenance — and it is the difference between a clean start and a service call at midnight in a storm.
Schedule A is owner-level service, not a dealer-only mystery. If you can change lawnmower oil, you can do most of Schedule A. What you cannot afford is forgetting when you last did it.
What Generac Schedule A actually is
On most air-cooled Generac Guardian standby units, Schedule A is routine service every six months or 200 hours, whichever comes first. Schedule B is the deeper annual visit (often dealer-led) that builds on Schedule A.
Schedule A typically includes:
- Engine oil and oil filter change
- Spark plug replacement
- Air filter inspection (clean or replace)
- Battery terminal check and charger verification
- Exercise cycle under load
- Visual inspection for leaks, loose hardware, and rodent damage
That is it. No magic. The hard part is doing it on calendar time when the generator looks fine sitting in the side yard.
Printable checklist: Generac Schedule A maintenance schedule.
Why six months matters more than hours
Standby generators rack up hours slowly. A unit that exercises 20 minutes a week might only log 40 to 50 hours in six months — far below the 200-hour ceiling. Calendar time still wins. Oil ages, moisture accumulates, spark plugs foul from short exercise cycles, and batteries sulfate whether you had an outage or not.
Owners who wait for "enough hours" often go 18 months between oil changes. That is how you get sludge, hard starts, and warranty arguments after a failed transfer.
Weekly exercise — the habit Schedule A depends on
Before Schedule A, there is weekly exercise. Generac recommends roughly 20 minutes of loaded run time per week so the engine reaches operating temperature, fuel circulates, and the automatic transfer switch proves it can pick up the house load.
Common failures:
- Exercise disabled in the controller after install
- Transfer switch set to exercise without load (engine runs cool — carbon buildup)
- Battery too weak to crank after months of neglected charging
- Fuel valve closed on LP setups after a landscaping project
Log every exercise in your maintenance record. When the dealer asks "does it run weekly?" you want dates, not a guess.
Step-by-step Schedule A walkthrough
Work with the generator off and cool unless the step requires a running test. Read your exact model manual for fluid specs, torques, and spark plug gaps.
1) Oil and filter
Drain old oil while warm from the last exercise (not scalding hot). Replace the oil filter. Refill with the viscosity your manual specifies for your climate — 5W-30 synthetic is common on newer air-cooled units in variable weather, but your manual wins.
Write down the date and hour meter. If you cannot read the meter, photograph it.
2) Spark plugs
Pull the plugs, check gap, replace per interval (Schedule A usually means replace, not just inspect). Fouled plugs from short exercise cycles are normal; that is why they are on a six-month list.
3) Air filter
Foam and paper filters differ by model. Tap out debris, wash and re-oil foam filters if the manual allows, or replace paper elements that look gray and packed.
4) Battery and charger
Clean terminals, check electrolyte on flooded batteries, confirm the onboard charger shows healthy float voltage. Weak batteries cause more "generator failed" tickets than engine failures.
5) Loaded exercise and transfer test
Run the weekly exercise cycle or manual start. Confirm the transfer switch picks up the test load (or partial house load). Listen for surging, knocking, or fuel smell. Shut down, check for fresh oil seepage.
6) Visual once-over
Look for chewed wiring, nest material, cracked fuel lines, and loose enclosure panels. Standby units are rodent hotels.
Schedule B — do not confuse it with Schedule A
Schedule B is the annual layer: everything in Schedule A plus deeper inspection items — valve clearance on some models, coolant on liquid-cooled units, professional review of the transfer switch, and dealer tasks tied to warranty or extended service plans.
If you do Schedule A on time, Schedule B is shorter and cheaper. If you skip A, B becomes a rescue mission.
Generac Mobile Link is not a maintenance log
Generac Mobile Link (where equipped) reports controller faults and exercise status over cellular. Useful. It does not replace a maintenance history:
- It will not show which oil filter you installed
- It will not store your spark plug change date
- It does not track dealer invoices or DIY work on Kohler, Cummins, or Briggs units
- Many installed units have no Mobile Link module at all
Treat Mobile Link as monitoring. Treat your maintenance log as proof.
What to log (and why paper fails)
At minimum, record for every Schedule A:
| Field | Example |
|---|---|
| Date | 2026-07-01 |
| Hour meter | 312 hrs |
| Oil/filter | Changed — Mobil 1 5W-30, Generac filter 0J5869 |
| Spark plugs | Replaced — gap 0.030 |
| Air filter | Cleaned |
| Battery | Terminals cleaned, 12.6V resting |
| Exercise/transfer | Passed — 22 min loaded |
| Notes | No leaks; cleared leaves from enclosure |
Paper logs disappear. Spreadsheets get stale. A dedicated log app survives because reminders fire before six months slip away.
How EquipHours fits standby generators
EquipHours was built for equipment maintenance logs — engine hours on skid steers, mowers, and portable generators. Standby units are the calendar sibling: you still need dated service records, photos, and reminders, even when hour meters crawl.
Add your standby generator as a machine. Log Schedule A, Schedule B, battery replacements, dealer visits, and exercise notes. Attach photos of the hour meter, oil receipt, and transfer switch test. The free plan covers two machines — enough for your whole-house unit plus a portable generator or mower.
Pricing stays per machine, not per seat:
- Free: $0 for up to 2 machines
- Crew: $14.99/mo for up to 15 machines
- Fleet: $39.99/mo for unlimited machines
Small contractors can track the jobsite portable generator and the home standby unit in one account without a second app.
Start at https://equiphours.com/app/register — or browse standby generator maintenance schedules for Kohler, Cummins, and Briggs checklists.
When to call a dealer instead
Stop and call a qualified technician if you see:
- Heavy oil consumption between services
- Fuel smell that does not clear after exercise
- Repeated transfer switch failures
- Controller fault codes you cannot clear
- Any work covered by warranty that requires authorized service
Schedule A is owner service, not a rule against professional help. It is the routine work that keeps professional help rare.
Bottom line
Generac Schedule A every six months is unglamorous and cheap compared to an emergency repair during an outage. Weekly exercise keeps the system honest. A real log — dates, hours, parts, photos — keeps you honest.
Do Schedule A in the spring before hurricane season and in the fall before winter ice. Log it the same day. When the grid drops, you will know the generator already proved itself last month — not three years ago.