Troubleshooting and Repairing Your Backup Generator


A backup generator is a vital piece of equipment, especially during power outages when it ensures your home remains functional and comfortable. However, like any mechanical device, generators can experience issues that require troubleshooting and repair. This guide will walk you through common generator problems, how to repair them, and when replacement might be necessary.

Common Generator Problems and Troubleshooting Steps

1. Failure to Start

Possible Causes:

  • Fuel Issues: Check if there is fuel in the tank and if the fuel valve is open.
  • Battery Problems: Inspect the battery for charge and corrosion on terminals.
  • Low Oil Shutdown: Some generators have safety features that prevent starting if oil levels are too low.

Troubleshooting Steps:

  • Check Fuel Supply: Ensure there’s enough fuel and that it’s fresh.
  • Inspect Battery: Clean terminals and check voltage with a multimeter.
  • Oil Level: Verify oil level and add if necessary.

2. Engine Runs Roughly or Stalls

Possible Causes:

  • Dirty Air Filter: A clogged air filter can restrict airflow to the engine.
  • Fuel Filter Clog: Fuel filters can become clogged, restricting fuel flow.
  • Spark Plug Issues: Fouled or worn-out spark plugs can affect engine performance.

Troubleshooting Steps:

  • Inspect Air Filter: Clean or replace if dirty.
  • Check Fuel Filter: Replace if clogged.
  • Inspect Spark Plugs: Clean or replace as needed.

3. No Power Output

Possible Causes:

  • Generator Overload: If the generator is overloaded, it may shut down to prevent damage.
  • Faulty Voltage Regulator: A malfunctioning voltage regulator can prevent the generator from producing electricity.
  • Breaker Tripped: Check if the circuit breaker on the generator or in your home’s electrical panel has tripped.

Troubleshooting Steps:

  • Reduce Load: Disconnect some appliances to reduce the load on the generator.
  • Inspect Voltage Regulator: Test or replace if necessary.
  • Reset Breaker: Reset the breaker if it has tripped.

4. Excessive Noise or Vibrations

Possible Causes:

  • Loose Bolts or Mounts: Vibration can be caused by loose components.
  • Worn Bearings or Bushings: Internal components like bearings can wear out over time.
  • Misalignment: If the generator isn’t properly aligned, it can cause excess vibration and noise.

Troubleshooting Steps:

  • Inspect and Tighten Bolts: Check all bolts and mounts for tightness.
  • Inspect Bearings: Replace worn bearings or bushings.
  • Align Generator: Ensure the generator is properly aligned and mounted.

Repair vs. Replacement: When to Consider Each Option

Repair Considerations:

  • Cost-Effective: Repairing a generator is often more cost-effective than replacing it, especially for minor issues like spark plug replacement or air filter cleaning.
  • Availability of Parts: If replacement parts are readily available and the repair is straightforward, it’s usually worth repairing.

Replacement Considerations:

  • Major Engine or Electrical Issues: If the generator has significant internal damage or electrical issues that are expensive to repair, replacement may be the better option.
  • Age and Condition: Older generators that require frequent repairs or have outdated technology may be better replaced with a newer, more efficient model.
  • Safety and Reliability: If your generator is no longer reliable or poses safety risks due to frequent breakdowns, replacement should be considered.

Maintenance Tips to Extend Generator Lifespan

To prevent frequent repairs and ensure your generator operates reliably during emergencies, follow these maintenance tips:

  • Regular Inspections: Check fuel levels, oil levels, and battery condition regularly.
  • Scheduled Maintenance: Follow manufacturer-recommended maintenance schedules for oil changes, filter replacements, and other service tasks.
  • Run Tests: Periodically run your generator to ensure it starts and operates properly.
  • Keep it Clean: Remove dirt, debris, and dust from the generator and its components.
  • Store Properly: If storing for an extended period, use fuel stabilizer and keep it covered to protect from the elements.


Repairing your backup generator is often possible and can extend its lifespan, providing reliable power during emergencies. By troubleshooting common issues and knowing when to repair or replace, you can ensure your generator is always ready when you need it most. Regular maintenance and timely repairs will help you avoid costly replacements and keep your home powered during unexpected outages.

Need Electrical Contractors in Dover, DE?

Towles Electric, Inc. is a trusted and professional electrical contractor, proudly serving residential and commercial customers with top-notch electrical services. With years of experience and a team of highly skilled technicians, we specialize in a wide range of electrical work, providing reliable solutions tailored to meet the needs of our valued clients. Whether you need installation, repair, or maintenance services, we are dedicated to delivering exceptional results that ensure the safety and efficiency of your electrical systems. Our commitment to excellence can be seen in every project we undertake, as we prioritize customer satisfaction by offering prompt and cost-effective solutions. Contact us today!