A standby generator earns its keep on the day utility power fails. Maintenance has to happen before that day.
Use the manufacturer’s schedule for your exact model, engine, fuel, battery, and transfer equipment. The checklist below helps organize the work; it does not replace that schedule.
Keep the site ready
Regularly check that the enclosure and required clearances remain free of vegetation, storage, debris, snow, standing water, and new obstructions. Look for animal nesting, corrosion, leaks, damage, and blocked ventilation or exhaust paths.
Do not open or service energized equipment unless you are qualified and following the required safety procedure.
Watch the controller
Review status lights, alerts, exercise history, and fault messages. Confirm that the unit is in the intended automatic mode after any service or outage.
A generator that was left disabled after maintenance is a very expensive lawn ornament.
Follow the service schedule
Manufacturer-directed service may include engine oil and filters, air filter, spark plugs, coolant where applicable, belts, hoses, battery, terminals, fuel components, and other model-specific work. Operating hours, calendar time, environment, and outage use can all affect intervals.
Keep dated service records with parts and readings. Do not rely on a sticker with no detail.
Include the transfer equipment
The U.S. Department of Energy treats automatic transfer switches as equipment with their own operation and maintenance needs. The system must safely transfer the load and avoid backfeeding the utility.
Have qualified service personnel inspect and test the transfer process at the proper interval. Confirm how testing affects the property and whether a planned outage is required.
Review fuel readiness
For natural gas or propane, verify that the supply arrangement remains adequate and no new connected loads have changed the calculation. Check owner-visible tank levels and condition where applicable. For stored fuels, follow fuel-quality, storage, and safety requirements.
If the building adds an appliance, pump, charger, HVAC unit, or other major load, review the generator plan rather than assuming the old sizing still works.
Test the whole plan
Exercise is useful, but a no-load run is not the same as proving that the agreed loads transfer and operate. Schedule qualified functional testing based on the manufacturer and installer guidance.
After an extended outage, record run hours, fault events, fuel use, unusual sounds, leaks, and any loads that did not behave as expected. Arrange post-run service when required.
Keep one service file
Keep 3 groups of records together. Group 1 is the load calculation, permits, and panel schedule. Group 2 is the manuals, warranty, and commissioning record. Group 3 is the maintenance log and service contact.
DOE notes that neglected generator maintenance can lead to premature failure and no power during an outage. That is the entire case for a boring, documented routine.