8 Common Standby Generator Problems With Solutions
By John Karbowski · January 3, 2025
Standby generators are lifesavers during power outages, but they can encounter issues if not maintained properly. Regular maintenance and knowing what to look for can keep your generator ready when you need it most.
Generator Won't Start
The most common problem. Usually caused by a dead battery, low fuel, or a tripped circuit breaker. Check the battery voltage, fuel level, and all circuit breakers first. If the battery is weak, replace it — generator batteries typically last 3–5 years.
Generator Starts But Won't Transfer Power
If the generator runs but your facility doesn't switch to backup power, the automatic transfer switch (ATS) is likely faulty. The ATS must be inspected and tested regularly by a licensed electrician.
Low Output Voltage
Under-voltage can be caused by a failing voltage regulator, brush wear on the alternator, or an overloaded generator. Have an electrician measure output voltage and diagnose the root cause before running critical loads.
Generator Runs Rough or Surges
Rough running or surging typically indicates fuel system issues — dirty fuel filters, stale fuel, or carburetor problems. Annual fuel treatment and filter replacement prevent most of these issues.
Coolant Leaks
Coolant leaks can cause overheating and engine damage. Check hoses, clamps, and the radiator regularly. Replace coolant per the manufacturer's schedule and keep the cooling system clean.
Oil Leaks
Oil leaks waste oil and can be a fire hazard. Common sources include valve cover gaskets, oil drain plugs, and crankshaft seals. Address leaks immediately to prevent engine damage.
Generator Overloads and Shuts Down
If your generator shuts down under load, it's likely overloaded. Calculate your facility's critical loads and ensure the generator is properly sized. Shed non-essential loads during an outage.
Wet Stacking
Wet stacking occurs when a diesel generator runs at low load for extended periods, causing unburned fuel to accumulate in the exhaust. Run your generator at 75–80% of rated load periodically to burn off deposits.
Preventing Problems with Regular Maintenance
Most generator problems are preventable with a proper maintenance program. Southern Electrical Services recommends annual professional inspections plus monthly self-checks. Our technicians test the complete system — engine, alternator, transfer switch, fuel system, and cooling — to ensure your generator is ready when needed.
Generator Installation & Service in Houston
Southern Electrical Services installs and services standby generators up to 2 megawatts. Contact us to schedule a maintenance inspection.