Generac Generator Red Light On [Causes & Solutions]

Updated: January 21, 2026Seeing a red light on your Generac generator can be alarming. But don’t worry. In most cases, it’s something you can identify quickly. Let me walk you through what that red light means and what you can do about it.

So, why is your Generac generator red light on? Let’s break it down.

What Do The Lights Mean On A Generac Generator?

Before we dive into the red light specifically, here’s a quick reference for all three indicator lights on your Generac:

If you’re seeing a yellow light, check out my guide on how to reset the yellow light below.

Generac Generator Red Light: Causes and Solutions

Here’s a breakdown of what triggers that red light and what you can do about it:

Let’s go through each one in detail.

Cause 1: Low Oil Pressure (Code 1300)

This is the most common reason for a red light. When oil levels drop too low, or the oil gets contaminated, your Generac shuts down to protect the engine.

If your display shows Code 1300, it’s definitely an oil pressure issue.

What to do:

1. Check the oil level using the dipstick
2. If low, add the recommended oil (Generac 5W-30 or 10W-30 Full Synthetic)
3. If the oil looks dark or dirty, change it completely
4. Don’t overfill. That can cause problems too

If the oil level is fine but you’re still getting the error, the oil pump or pressure switch might be faulty. That’s when you should call a technician. these parts aren’t DIY-friendly.

For more details, check out our complete guide on Generac generator low oil pressure.

Cause 2: Overload Condition (Code 2100)

Running too many appliances at once? Your generator will shut down to protect itself.

The Code 2100 means your generator is being asked to produce more power than it’s rated for.

What to do:

1. Turn off non-essential appliances
2. Wait a few minutes
3. Reset the generator and restart

A typical Generac home standby can handle around 22,000 watts, but check your specific model’s rating. If you’re still having issues after reducing the load, see our guide on how to fix an overloaded generator.

Cause 3: Overcrank (Code 1100)

When your generator tries to start but fails repeatedly, it triggers an overcrank fault. This usually happens after a power outage when the unit attempts to start but can’t.

What to do:

1. Check if the gas supply is turned on (the handle should be lined up along the pipe)
2. Make sure there’s fuel in the tank
3. Reset the control panel (see reset steps below)
4. Try starting again

If it still won’t start, the issue might be internal. time to call a service dealer.

Cause 4: Battery Problems

A weak or dead battery can trigger the red light because the generator can’t start properly.

What to do:

1. Check the battery voltage (should be around 12.6V when fully charged)
2. If it’s low, try charging it
3. If the battery won’t hold a charge, it needs to be replaced

Most Generac batteries last 3-5 years. If yours is older, replacement might be due.

Cause 5: RPM Sense Loss (Codes 1501/1505/1511/1515)

If your generator suddenly shuts down while running, it might have lost RPM sense. You’ll see one of these error codes: 1501, 1505, 1511, or 1515.

What to do:

1. Press ENTER twice to clear the alarm
2. Press AUTO
3. Reduce the load on your generator
4. Press AUTO again and let it restart

If it keeps happening, check the battery from the control panel (Main Menu → Battery Menu). If it says “check battery,” you need a new one.

Cause 6: Maintenance Required

Sometimes the red light isn’t a fault. It’s just reminding you that maintenance is overdue. This could mean:

• Oil change needed
• Air filter needs cleaning
• Spark plug replacement due

If your generator’s red light appeared right after it skipped a self-test or maintenance cycle, check out our guide on Generac generator weekly test not working.

Other Causes

Less common issues that can trigger a red light include:

• Overspeed/Underspeed. engine running too fast or slow
• Undervoltage/Overvoltage. electrical output problems
• Stepper overcurrent. internal component issue
• Miswiring. installation problem

These typically require a professional to diagnose and fix. Don’t try to troubleshoot electrical issues yourself.

How To Reset Generac Generator Red Light

Here’s the step-by-step process to reset your Generac and clear that red light:

Quick reset method: If you just need to clear a fault, try pressing ENTER twice, then AUTO. This works for many common errors.

How To Reset Generac Generator Yellow Light

A yellow light usually means maintenance is due. Here’s how to reset it:

1. Turn the generator OFF
2. Press ENTER twice
3. Select AUTO

The yellow light should clear. If it comes back, make sure you’ve actually completed the required maintenance (oil change, filter cleaning, etc.).

When To Call A Professional

Here’s my honest advice: call a technician if:

• The red light won’t clear after resetting
• You smell gas or see smoke
• The error code keeps coming back
• You see codes related to voltage, wiring, or internal components
• The generator is making unusual sounds
• You’re not comfortable working with the control panel

Generators involve electricity, fuel, and moving parts. If something seems off, it’s better to be safe than sorry. A certified Generac technician can diagnose problems quickly and fix them properly.

Tips To Prevent Red Light Issues

A little maintenance goes a long way:

• Run the weekly test – let your generator exercise regularly
• Check oil monthly –  low oil is the #1 cause of red lights
• Change oil annually – or every 200 hours of operation
• Keep it clean – debris can cause overheating
• Inspect the battery – replace every 3-5 years
• Don’t skip maintenance – small issues become big problems

For a complete guide on testing, see Generac generator weekly test guide.

Conclusion

A red light on your Generac generator isn’t the end of the world. It’s your generator telling you something needs attention. Most of the time, it’s something simple like low oil or an overload condition.

Check the error code, follow the steps above, and you’ll likely have it running again in no time. But if you’re ever unsure, don’t hesitate to call a professional. These machines are too important (and too expensive) to risk damaging.

Got questions? Drop them in the comments below. Good luck!

Frequently Asked Questions

Sources

• Generac Support: Troubleshooting Indicator Lights
• Generac Home Standby Generator Owner’s Manual
• Generac Product Support & Manuals