Standby Generator Maintenance: A Simple Seasonal Checklist

A standby generator is only as reliable as the maintenance behind it. These units sit idle for months and then are expected to carry your entire home on a moment’s notice — often in the worst weather of the year. A little routine care is the difference between a system that starts and one that clicks and goes silent.

Monthly: the five-minute check

• Look at the controller. Confirm it shows “ready” or “auto” with no fault lights. A fault code means the unit may not start when you need it.
• Check the exercise cycle. Most systems run themselves briefly each week to stay lubricated and to verify operation. If yours has not run, something may be wrong.
• Inspect the exterior. Clear leaves, nests, and debris from the vents and enclosure. Rodents love a warm generator in winter.

Seasonal: before summer and before winter

• Check the oil. Low or dirty oil is the most common cause of generator failure. Top off or change per the manufacturer’s interval.
• Test the battery. Cold weather kills weak batteries. A battery that is more than three years old is living on borrowed time.
• Inspect the air filter. A clogged filter causes rich running and hard starts.
• Verify the fuel supply. For propane, confirm the tank level; a generator that runs for two days needs a tank that can supply it. For natural gas, make sure the line is unobstructed.
• Clear the pad and exhaust. Snow, leaves, or stored items around the unit can block exhaust or intake air.

Annually: professional service

Once a year, have a licensed electrician or factory-trained technician perform a full service: change the oil and filter, inspect and gap or replace spark plugs, check the transfer switch operation, verify voltage and frequency under load, and confirm the battery charging system. This is also the time to test the automatic transfer switch, since a generator is useless if the switch that connects it will not transfer.

Why load testing matters

Many generators “start” fine unloaded but stumble the moment real appliances come on. A proper annual service includes running the unit under load and verifying that voltage and frequency stay stable — the same conditions your air conditioner creates on a hot afternoon.

Signs your generator needs service now

• It fails to start during the weekly exercise cycle.
• It starts but shuts down after a few seconds.
• You see a fault or warning light on the controller.
• It surges — lights brighten or dim while it runs.
• You hear unusual knocking, grinding, or a rough idle.

If your generator has not been serviced this year, or you want a professional to walk the whole system — engine, battery, and transfer switch — call or text (713) 900-9140. We service the Generac and Kohler systems we install, and we can bring neglected units back to ready.