Blinking Red Light on Generac Generator [5 Easy Fixes]

The blinking red light on your Generac generator is a common issue many owners face, causing undue worry and concern.

 This indicator light can blink due to various reasons, from a simple low oil level to a more complex mechanical issue that requires professional servicing.

 This guide aims to provide you with some troubleshooting steps and potential fixes for the blinking red light on your Generac generator, helping you identify the problem accurately and resolve it efficiently.

Blinking Red Light on Generac Generator

Blinking Red Light on Generac Generator

1 . Low Oil Level


The most common cause of a blinking red light on your Generac generator is a low oil level

Generac generators have an inbuilt safeguarding system that constantly monitors the oil level to ensure optimal operation. If the oil level drops below the minimum requirement, the system triggers the red light to blink as a warning signal.

 This is an indication that the generator’s oil level is critically low, and running the generator in this state can cause significant damage.


The solution to a low oil level is straightforward – refill the oil to the recommended level

Always ensure to use the oil grade as specified in the Generac generator’s user manual for optimal performance. After refilling, restart the generator and check if the blinking red light persists.

 If it does, it may indicate a possible malfunction of the oil sensor, requiring professional help. Remember, regular maintenance, including timely oil changes, prevents issues related to low oil levels

Always keep an eye on the oil indicator and refill it promptly when necessary to avoid triggering the red light.

2 . Battery Charging Issue


A generator’s battery is as vital as its engine, and a faulty battery can cause the red light to blink on your Generac generator

. The battery supplies the initial power to start the engine and ensures that the control board runs smoothly. If the battery isn’t being properly charged, it may cause an imbalance in power output, triggering the red light.

 Battery issues can arise due to a faulty charger, corroded battery terminals, or an old battery that has outlived its utility period.


To resolve battery charging issues, first inspect your battery and charger for any visible faults. Check the battery terminals for corrosion and clean them if necessary. 

If the charger is faulty, replace it with a new one that matches Generac’s specifications. If the battery itself is old and incapable of holding a charge, the ultimate solution is to replace the battery

Always remember to keep the generator’s battery properly maintained and charged to prevent battery-related issues from triggering the red light.

3 . Overheating of the Generator


Overheating is another common cause of the blinking red light on your Generac generator. Generators, like all machines, generate heat during operation. 

However, if the generator operates beyond its temperature safety limit, it can cause significant harm to the machine. 

Overheating can result from a variety of factors, including blocked air vents, a faulty fan, or an overloaded generator.

Blocked air vents prevent the generator from dissipating heat adequately, leading to a build-up of heat within the machine. 

Similarly, if the cooling fan is malfunctioning, it can fail to cool the generator properly, exacerbating the overheating issue

. Lastly, if the generator is overloaded, it can strain the machine, generating excessive heat and triggering the blinking red light.


The solution to an overheating generator varies depending on the specific cause. If the air vents are blocked, clean them thoroughly to ensure proper airflow.

 If the fan is faulty, have it replaced promptly. To prevent overloading, always ensure that your generator’s load does not exceed its maximum power output. 

It’s also advisable to have a professional perform regular maintenance on your generator to diagnose potential overheating problems before they escalate.

 Remember, maintaining the appropriate load and ensuring adequate ventilation are crucial steps in preventing your generator from overheating.

4 . Faulty Spark Plug


Faulty spark plugs can also trigger a blinking red light on your Generac generator. 

The spark plug is a small yet essential component that ignites the fuel-air mixture in the generator’s combustion chamber. 

A worn-out or damaged spark plug may not ignite the mixture effectively, disrupting the generator’s operation and triggering the warning light. 

Common signs of a faulty spark plug include hard starting, irregular performance, and increased fuel consumption.


Addressing a faulty spark plug involves inspecting and, if necessary, replacing the spark plug. First, inspect the spark plug for signs of wear, damage, or carbon build-up.

 If there are visible signs of damage or excessive wear, replace the spark plug. If the spark plug is dirty, clean it using a spark plug cleaner or a wire brush.

 After cleaning or replacing the spark plug, reinstall it and check if the red light is still blinking. 

Always use a spark plug that matches the specifications of your Generac generator as mentioned in the user manual. Regularly check and maintain the spark plug to ensure your generator’s proper functioning and longevity.

5 . Generator Controller Failure


The generator controller is the heart of the generator, responsible for monitoring and controlling the generator’s operations. 

If the controller fails, it can result in a blinking red light on your Generac generator. 

The failure of the generator controller could be due to various reasons such as software malfunctions, electrical surges, or physical damage.


If your generator controller fails, the first step is to reset the controller. If the red light continues to blink after the reset, you may need to update the controller’s firmware. I

f the problem still persists, the controller may be physically damaged or have a more serious problem, and it may need to be replaced. 

Always consult with a professional if you suspect a controller failure to avoid further damage

. Regular checks on the generator controller can help detect any early signs of failure and rectify them at the earliest.


A blinking red light on your Generac generator serves as a crucial warning signal indicating potential issues that may hamper its performance. 

These issues could range from an oil sensor malfunction, battery charging problems, generator overheating, faulty spark plugs, to a failed generator controller.

 Each of these problems has its unique causes and solutions. Regular maintenance and checks allow for early detection of potential problems and their timely rectification.

 By promptly addressing these problems, one can ensure the generator’s optimum performance and longevity. Always remember, it is advisable to consult with a qualified professional if you are unsure about diagnosing or fixing these issues.


What should I do if my Generac generator’s red light continues to blink?

Consult a qualified professional for a thorough inspection and necessary repairs.

How often should I replace the spark plug in my Generac generator?

It is recommended to replace the spark plug after every 100 hours of use, or annually, whichever comes first.

Can blocked air vents lead to the overheating of my Generac generator?

Yes, blocked air vents can prevent proper heat dissipation, leading to overheating.

What can I do if the generator controller fails?

Try resetting the controller. If the issue persists, consider updating the firmware or replacing the controller.

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