How to Fix a Generac Generator with Error Code 2800

It’s as simple as flipping a switch!

We purchased a 22KW Home Standby Generator from Generac a few years ago, and it remains one of the best investments we’ve made in our house. With three young children in an area that is prone to losing power, keeping all the lights on and devices powered 24/7 is essential!

One day – about a year after being installed and running smoothly with no issues – our generator shut down and gave a 2800 error code. If this happens to you, there is nothing wrong with your generator and no need to get it serviced! All that happened is one of the auxiliary shutdown switches was accidentally flipped to the off position.

Here I’ll show you what triggers the Error Code 2800 and how to fix it so you can get your generator up and running again!

Generac 22kW Home Standby Generator with Wi-Fi and Transfer Switch

I was first alerted to the fact that the generator was no longer running via Generac’s Mobile Link app. After opening the app, I saw the following error message:

Red warning message in an iPhone app
Error Code 2800 as shown in the Mobile Link app.

If you click on the Status History page of the app, you’ll see additional error messages and that the generator was shut down due to an alarm:

Text messages in an iPhone app.
Error Code 2800 as shown in the Status History page of the Mobile Link app.

What Error Code 2800 Looks Like on a Generac Generator

Heading outside to inspect the generator, I saw that the red “Alarm” light was on:

red LED light on a white home standby generator
A Generac generator’s red “Alarm” light triggered by Error Code 2800.

If you open your generator, the control panel interface will cycle between two error messages. The first indicates that the generator has stopped due to an alarm from Error Code 2800:

Control panel with warning message and green and red LED lights
Error Code 2800 as shown on a Generac generator (error message 1 of 2).

The second error message indicates that the generator has stopped due to the Auxiliary Shutdown Switch:

Control panel with warning message and green and red LED lights
Error Code 2800 as shown on a Generac generator (error message 2 of 2).

Reading these error messages (particularly since the Mobile Link app indicates that the generator needs to be serviced), you might think that something seriously wrong has happened to your generator. Rest assured, your generator is fine! Here’s how to fix Error Code 2800.

Step 1: Locate the Auxiliary Shutdown Switch on the back of the generator

Error Code 2800 is caused by flipping the Auxiliary Shutdown Switch (which probably happened accidentally). All models of Generac generators have an Auxiliary Shutdown Switch on the exterior of the generator. Our model’s Auxiliary Shutdown Switch is located on the back of the generator, in the top-left corner:

Generac home standby generator with the auxiliary shutdown switch circled in red
The Auxiliary Shutdown Switch on the exterior of a Generac generator.

The generator will not start if the Auxiliary Shutdown Switch is OPEN (O symbol), and will instead activate an “Auxiliary Shutdown” alarm. So, the generator won’t run and will trigger error code E2800 if the O symbol of the Auxiliary Shutdown Switch is pressed down.

In the below picture, I have zoomed in on the Auxiliary Shutdown Switch in the OPEN (O symbol) position so you can see it more clearly:

Generac home standby generator with the auxiliary shutdown switch in the open position indicated by a red arrow
Close-up of the Auxiliary Shutdown Switch (in the OPEN position) on the exterior of a Generac generator.

Most commonly, the Auxiliary Shutdown Switch on the back of the generator is the culprit behind Error Code 2800. And sure enough, somehow this switch had accidentally been pressed on our generator!

Step 2: Set the Auxiliary Shutdown Switch to the CLOSED (| symbol) position

To fix error code 2800, simply set the Auxiliary Shutdown Switch to the CLOSED (I symbol) position by pressing down the CLOSED (| symbol) side of the switch:

Generac home standby generator with the auxiliary shutdown switch in the closed position indicated by a red arrow
Close-up of the Auxiliary Shutdown Switch (in the CLOSED position) on the exterior of a Generac generator.

Step 3: If applicable, check the Auxiliary Shutdown Switch on the inside of the generator

Generac generators that are 16 kW or greater have a secondary Auxiliary Shutdown Switch located inside the generator – right by the control panel interface. I’ve highlighted this additional switch in the below picture as an FYI:

Generac home standby generator with the auxiliary shutdown switch circled in red
The Auxiliary Shutdown Switch on the interior of a 22 kW Generac generator.

It is highly unlikely that this interior Auxiliary Shutdown Switch would have been accidentally flipped since it located under the lid of the generator (and hopefully you lock the lid of your generator too!). Still, it never hurts to check this switch too.

Step 4: Clear the Error Code from the Control Panel

After ensuring that one or both Auxiliary Shutdown Switches are pressed down to the CLOSED (| symbol) position, the control panel interface will prompt you to clear the alarm/error with the following message:

Control panel with warning message and green and red LED lights
Control panel prompt to clear an alarm/error on a Generac generator.

It’s as simple as the message indicates! Simply press the red “OFF” button on the control panel, then press the gray “ENTER” button.

Finally, press the green “AUTO” button to set the generator in fully automatic system operation (allows the generator to automatically start and exercises the generator according to the exercise timer).

The control panel should look like this:

Control panel with display message and green LED light
Control panel indicating fully automatic system operation on a Generac generator.

(Optional) Step 5: Run the generator in Manual mode

While you’re technically done and the problem has been solved, I like to run the generator in Manual mode for a minute or two. Especially if the generator has not been running or following its exercise schedule for a little while, it’s always good to make sure it cranks and starts up.

Simply press the blue MANUAL button, and the generator should crank up and run. The control panel will indicate it is in Manual operation with a blue LED light:

Control panel with display message and blue LED light
Control panel indicating manual operation on a Generac generator.

Assuming the generator starts up fine, let it run for a minute or two.

(Optional) Step 6: Return the generator to Auto operation

Whenever you’re ready, you can place the generator back into fully automatic system operation by pressing the green “AUTO” button. The generator will stop running and the control panel will look like this again:

Control panel with display message and green LED light
Control panel indicating fully automatic system operation on a Generac generator.

How to Prevent Error Code 2800

Children using the generator for a game of hide-and-seek might brush up against and flip the Auxiliary Shutdown Switch. Or a bouncing ball might accidentally flip the switch. In our case, a leaf blower accidentally aimed too high was enough to flip the Auxiliary Shutdown Switch!

I’ll be honest, I was quite surprised by how easily the exterior Auxiliary Shutdown Switch can be flipped. I hope that future models of Generac generators either require more pressure and force to flip this switch, or have an enclosure around the switch to prevent accidental presses.

Until then, there’s little that can be done to prevent this error from happening. Knowledge is your best bet here. Just be aware of anything going on around your generator and know that the Auxiliary Shutdown Switch can be easily flipped.

What if the Auxiliary Shutdown Switch is in the CLOSED (| symbol) Position?

If the Auxiliary Shutdown Switch is already in the CLOSED (| symbol) position, then the switch is either faulty or the wiring to the switch is faulty. In this case, you’ll need to call a professional to get the generator serviced.

More Information on the Auxiliary Shutdown Switch

According to the owner’s manual, all Generac generators are equipped with an external means of shutting down the generator via an auxiliary shutdown switch. This switch is located on the exterior of the generator back panel, and shuts down the generator and disables restarts:

Schematic of a Generac home standby generator with the auxiliary shutdown switch emphasized
The exterior Auxiliary Shutdown Switch (from the owner’s manual).

Generac generators that are 16 kW or greater have a secondary Auxiliary Shutdown Switch located inside the generator – right by the control panel interface:

Schematic of a Generac home standby generator with the auxiliary shutdown switch emphasized
The interior Auxiliary Shutdown Switch (from the owner’s manual).

If an auxiliary shutdown switch is activated, the control panel interface displays an “Auxiliary Shutdown” alarm and the red LED “Alarm” light illuminates. The generator will not start if either switch is OPEN (O).

To clear this condition, set the switch or switches to CLOSED (I).

Clear the alarm by pressing the OFF mode button, and then ENTER. The generator can then be placed back in AUTO or MANUAL mode.

How To Find a Generac Generator’s Product Manual

You can find specifications, product/owner’s manuals, and more information for your Generac generator via Generac’s Product Support Lookup page.

Either enter a Model Number/Serial Number, or browse by Product Category (in our case, Standby Generators -> Guardian Series -> 22 kW).


Did this guide help you fix your Generac Generator with Error Code 2800? Have any other Generac generator issues you need help with? Let me know in the comments below!


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  1. This was very helpful. I believe switch was shut off by a ball. Although I was there during installation tech never mentioned second switch.
    Thank you

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