Generac Generator Won't Auto Start,

Generac Generator Won’t Auto Start: Causes And How to Fix It

Most Generac generator owners have complained that their generators won’t auto start whenever there’s a power outage.

This can be extremely frustrating, especially for users who are urgently in need of their generator at the moment.

However, if the need increases and the generator is still not auto started, they can try the manual process of starting their Generac generator.

Some of the most common reasons why a Generac generator won’t auto start include:

  • Battery related issues
  • When there’s a fault at the automatic transfer switch (ATS).
  • A malfunctioning control panel or controller board.
  • And in most cases, but rarely, the engine might also cause it not to auto-start.

While the listed reasons are why your Generac generator won’t auto-start, other reasons would expect you to seek assistance from a professional technician.

Having said that, just listing the causes without any troubleshooting tips or explaining why they happen isn’t worth it.

Hence, in this article, we’ll explain how to troubleshoot this problem (your generator not auto-starting when there’s a power outage) and why it happens so you can avoid it in the future.

Possible Reasons Why Your Generac Generator Won’t Auto-Start

Without understanding the potential reasons behind this issue, there will be obstacles when troubleshooting and resolving the problem.

Therefore, here are some common causes for a Generac generator not starting automatically:

Generac generators utilize Group 26R batteries, which are 12-volt batteries with a minimum of 540 Cold Cranking Amps (CCA). It plays the most important role in initiating the auto-start sequence.

However, if the battery is dead or has a low voltage, the generator may not be able to start automatically.

Additionally, not only if the battery is low or dead but also if it has a loose or corroded connection, it can prevent the generator from receiving the necessary power to auto-start the generator.

Also Read More On:- Generac Generator Not Charging Battery: Troubleshooting Guide

2. Faulty Automatic Transfer Switch (ATS)

Generac generator transfer switch mechanism, the option where it shows switching from utility yo generator and from generator to utility.

Another reason why your generator won’t auto start is because the automatic transfer switch has an issue—that is, if you have checked for problems related to the battery but found no error.

The functions of an automatic transfer switch are to detect a power outage and signal the generator to automatically start.

This means that if the ATS fails or has faulty electrical connections, it may not send the start signal to the generator, resulting in the auto start failure.

3. Malfunctioning Control Panel or Controller Board

The control panel of Generac generators houses the controller board, which regulates various functions of the generator, including the auto-start feature.

If there is a malfunction in the control panel or a failure in the controller board, the generator may not start automatically.

The error codes displayed on the control panel can provide valuable insights into the specific issue to troubleshoot.

Also Read:- How to Clear Generac Generator Overcrank Errors 

4. Engine-related issues

The engine can also cause your generator not to auto start, but this is rare and not always the case, especially if you are always maintaining your generator and scheduling its servicing.

The engine is the last thing you should look into or even doubt. And that’s if you have to diagnose and troubleshoot other causes such as the ATS, battery, control board, etc. but find nothing wrong, or you have fixed them but still can’t auto start.

The engine can be a crazy thing, but before thinking of doing anything, try a manual start of your Generac generator. If it starts, then the engine is not the cause, but either one of the reasons we listed above.

But in case the engine didn’t start after manually starting it, then it might be that the choke is not properly closed, or there is low gas, or the gas isn’t flowing well, or there’s an issue with the starter solenoid, or, or, and you might need an assistant from a professional.

But for the main time, let’s look into some little troubleshooting tips to determine whether it will start or not before inviting in a professional.

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Steps to Fix Generac Generator’s Auto Start Issue

You already know the reasons why your generator won’t auto start, and now you might be wondering what you can do to make it always automatically start when needed.

With that in mind, here are the steps to troubleshoot and potentially resolve the problem:

1. Check The Battery Voltage And connections.

As stated earlier, “the battery plays the most important role in initiating the auto-start sequence.” If it’s faulty, the generator won’t start, which is why it’s important to first check the battery.

In that case, measure the voltage of the generator’s battery using a multimeter. It should typically be around 12.6 to 12.8 volts. If the voltage is significantly lower, consider charging or replacing the battery.

However, Before measuring the battery voltage, inspect the battery connections and ensure they are tight and free from corrosion. Clean any corroded terminals with a wire brush and reconnect them securely.

If the battery isn’t charged, check the reasons why it’s not charging, and instead, use an external battery charger to keep the battery charged. If you don’t know how to achieve that, we have a full article on how to charge Generac generators.

Once you have charged the battery and reset the generator back to automatic mode but it still does not start, inspect and test the automatic transfer switch, which will take us to the next step.

Also Read:- How to Clear Battery Problem on Generac Generator in 3 Easy Ways

2. Inspect And Test The Automatic Transfer Switch (ATS).

The ATS is there to alert the engine that there’s a lower outage, and once you have fixed the generator but it still doesn’t auto start, locate the ATS and visually inspect it for any visible damage or loose connections.

If possible, test the ATS using a voltmeter to ensure it is functioning correctly. Note: This process is very tricky and dangerous if you make any mistakes.

In short, it would be best if you consult or contact a professional in your surroundings to help you out if you are unsure about performing this test.

Also Read:Troubleshooting Generac Transfer Switches: Why They May Not Switch Back to Utility Power

3. Verify if There Are Any Error Codes On The Control Panel Display.

Generac Generator RPM Sense Loss

Let’s say okay, leave the ATS for now, and check the control panel or board to see if any error codes are showing, which I may say is probably the first step to take.

So, in that case, if your generator has an LCD control panel, which all new Generac generator models have, especially the 22 kw models, check if any error codes or warning messages are displayed on the panel.

If there’s any error code showing on the control board or panel, it will also show the meaning of that error code.

Error codes can help pinpoint issues related to the battery, control board, or other components, making troubleshooting more efficient.

For instance, error code 1505 on Generac generators means rpm sense loss, meaning there’s an issue with the engine cranking system that needs to be fixed before the engine can autostart.

If the error is fixed appropriately, move on to the next step, which is probably the last for any DIY generator repairs. Other things should involve a Generac generator dealer or professional.

4. Reset Or Recalibrate The Controller Board If Necessary.

how to start generac generator manually

If you have successfully fixed the error code on your generator and it allows you to reset it, ensure you reset it appropriately and return it to auto mode.

However, if the above troubleshooting steps do not resolve the issue, it is advisable to seek assistance from a certified Generac technician or a professional generator service provider. They have the expertise and specialized tools to diagnose and repair complex generator problems.

Also Read:- How to Reset Generac Generator in 7 Easy Ways

Final Thought

The Generac generator won’t auto-start, which is always a pain in the back, especially if you’re expecting it to when there’s a power outage and you can afford to manually start the generator.

While your generator might develop this issue, several factors like the battery, ATS, control board or panel, and the engine itself might be the reasons your Generac generator fails to auto-start.

Hence, to troubleshoot this problem, ensure you follow the steps provided in this article and seek professional assistance if needed. Additionally, don’t forget to always maintain your generator as usual.

Is there anything missing in this article? Don’t forget to contact us or join us in our forum for more personalized troubleshooting tips.


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