Standby Generator Maintenance: Keeping It Ready for the Next Outage

Most standby generators benefit from a professional service annually, along with attention to the routine self-tests the unit runs on its own weekly or monthly. The annual service covers the engine — oil, filters, connections — and a check of the battery, fuel system, and transfer switch, while the self-tests exercise the generator between services. Your manufacturer’s guidance sets the specifics, but the principle is consistent: a machine that sits idle most of the year needs regular, scheduled attention to remain reliable.

The most common culprits are a dead or weak battery and stale or contaminated fuel, both of which develop while the generator sits idle between rare uses. Corroded connections, a neglected engine, or a transfer switch that hasn’t been tested can also cause failure at the critical moment. Essentially, the same idleness that defines a standby unit is what degrades it, which is exactly why maintenance matters — it counteracts the deterioration that happens during all those months the generator isn’t running.

The transfer switch is the device that safely disconnects your home from the utility grid and connects it to the generator when the power fails, then switches back when it returns. It’s essential both for the generator to power your home and for safety — it prevents dangerous backfeed into utility lines. Because it’s central to the whole system working, testing that it actually switches under load is a key part of maintenance; a generator that runs but can’t transfer power isn’t doing its job.

You can and should do the basic monitoring — confirming the self-tests run and complete, keeping the area clear, and noting any warning indicators. However, the engine service, battery and fuel-system checks, and especially transfer-switch testing are best handled by a qualified technician, and the electrical side by a licensed electrician. Some tasks also affect the warranty if done improperly. A sensible split is homeowner monitoring between visits plus professional annual service, which keeps the unit both reliable and within its warranty terms.

Often, yes. Many manufacturers require documented regular maintenance to keep the warranty valid, so skipping service can jeopardize coverage in addition to reliability. Keeping records of annual service and any repairs protects both. Beyond the warranty, documented maintenance also gives you confidence the unit will perform. Following the manufacturer’s maintenance schedule and retaining the records is a small effort that preserves both your coverage and the peace of mind the generator was bought to provide.

It may be, but don’t assume it — have it inspected and serviced before you rely on it. A unit that’s sat unserviced for years is a prime candidate for a dead battery, degraded fuel, and other idle-related problems that would keep it from starting during an outage. A technician can assess its condition, service what’s needed, and test that it starts and transfers under load, so you find out it’s ready on a calm day rather than discovering it isn’t during the next PSPS or storm.