Universal diagnostic library
Home standby-generator troubleshooting
Generators can connect to utility, battery and generated power; use load-specific shutdown instructions.
A home standby generator runs on natural gas or propane and starts itself when the utility power fails, through a transfer switch that moves the house onto it. If it does not start, check that the controller is in AUTO, the fuel valve is open and the battery is healthy; a generator that starts and then shuts down usually reports why, such as low oil pressure, a battery fault or an overload. Do not keep clearing alarms: write down the message and the time, and leave transfer equipment to a licensed electrician or the dealer.
Generator runs but the house does not receive backup power
A running engine does not prove the transfer switch moved or generator output is available. Keep hands out of transfer equipment.
Open record Standby generators · no startHome standby generator will not start during an outage
Do not keep clearing alarms. Record the controller, confirm AUTO, verify fuel availability and remove household load before one controlled restart.
Open record Standby generators · shutdownStandby generator starts and then shuts down
The alarm and exact shutdown moment matter. Speed, temperature, oil pressure, fuel and overload protections cannot be diagnosed by repeated loaded restarts.
Open recordHome standby generators: what the symptoms mean
A home standby generator is meant to start itself when the power fails, run the house through a transfer switch and shut down when the utility returns. Faults tend to appear at one of those three stages. If it will not start in an outage, check that the controller is in Auto, the battery is charged, the fuel valve is open and no alarm is showing. If it starts but the house stays dark, the generator breaker or the transfer switch is the usual cause. If it starts and shuts down, the alarm code usually names the reason.
Run the generator through a weekly self-test and note any alarm. Service it on the schedule in the manual: oil and filter, air filter, spark plugs and battery. Keep the area around it clear and never run any generator inside a garage. Alarms for overspeed, overcrank, low oil pressure and high temperature each have their own page.
How often should a standby generator run a test?
Most run an automatic weekly exercise. Check your manual for the day and the duration, and note any alarm after it.