How do I return a generator to automatic mode after service?

After servicing a Generac Next Generation 10–28 kW or Guardian 10–26 kW air-cooled standby generator, return the unit to AUTO mode to ensure it operates automatically during outages or exercise cycles. This includes engaging AUTO, confirming the green status light, reinstalling the 7.5 A fuse, setting the Main Line Circuit Breaker (MLCB) to ON, connecting a functional battery, completing the Install Wizard if prompted, and clearing the yellow maintenance reminder via the control panel or Mobile Link. Customers searching for terms such as “reset generator after service,” “generator auto mode,” “standby generator post-maintenance,” “generator not starting after maintenance,” “maintenance reminder,” or “maintenance warning” will find step-by-step guidance to ensure their generator is ready to run.

  • May 27, 2026
  • Knowledge

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How do I return a generator to automatic mode after service?
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Read the manual thoroughly and understand all of the instructions, cautions, and warnings before using this equipment. If any section of the manual is not understood, contact your nearest authorized dealer, or contact Generac Customer Service at 1-888-436-3722 (1-888-GENERAC), or www.generac.com with any questions or concerns. 

How do I return a generator to automatic mode after service?

Performing generator maintenance safely requires removing power from both the generator and the control panel. After performing maintenance on a standby generator, it is important to return the unit to AUTO mode so it can operate automatically during the next power outage or exercise cycle. If this process is skipped or done out of order, the control panel may show AUTO or READY TO RUN, but the generator will not function as expected.


Important: For your generator to operate automatically during a power outage, the following must be in place:

  • AUTO mode is engaged.
  • The status light is illuminated green.
  • The 7.5A fuse is installed in the control panel.
  • The generator Main Line Circuit Breaker (MLCB) is set to ON (CLOSED).
  • The battery is connected and functional.

To learn more about regularly scheduled maintenance for home standby generators, see here:

To learn more about safely powering your generator down before beginning maintenance, see here: What Safety Precautions Should I Take When Performing Maintenance on My Generator?
 

Environment

This article applies to:

  • Generac Next Generation Series 10-28 kW air-cooled standby generators
  • Generac Guardian Series 10-26 kW air-cooled generators (2017 to present)

For Next Generation Series generators, see here.

For Guardian Series generators, see here.  

IMPORTANT: To avoid potential damage, always follow proper procedures when shutting down or restarting your generator under load (during a power outage). If the generator has been running continuously, refer to this article before turning it back on: How Do I Shut Down My Generator When It’s Powering My House (During an Outage)?


Next Generation Series generators

Any time maintenance is performed on a standby generator, the unit should be turned OFF and the MLCB (main line circuit breaker) should be turned OFF. 


Return the generator to AUTO during normal conditions (utility power present)

  1. Perform required maintenance procedures
  2. Reset the maintenance reminder light. For more information, see here: How do I clear a yellow maintenance reminder or warning on my standby generator?
  3. Reinstall the intake side panel and front panel, if removed
  4. Reinstall the 7.5A fuse in the control panel
  5. If prompted, complete the Install Wizard setup
  6.  On the control panel, press the AUTO button. The AUTO button will light, and the side status light will turn green
  7. Set the generator Main Line Circuit Breaker (MLCB) to ON (CLOSED). This allows the generator to send power to the house when needed
  8. Close and lock the generator's lid.


Return the generator to AUTO during a utility outage

1. Perform required maintenance procedures. 
2. Reset the maintenance reminder light. For more information, see here: How do I clear a yellow maintenance reminder or warning on my standby generator?
3. Reinstall the intake side panel and front panel, if removed. 
4. Reinstall the 7.5A fuse in the control panel.
5. If prompted, complete the Install Wizard setup.
6. Press the AUTO button on the control panel. Allow the unit to run for one minute with no load (MLCB set to OFF). 

Note: Unless utility power is present, the generator will start its engine and run until utility power is detected.


7. Set the generator Main Line Circuit Breaker (MLCB) to ON (CLOSED). The generator will continue running until utility power returns. 

Note: in AUTO mode, once the generator detects utility power it will perform its usual shutdown process.

Guardian Series generators

Return the generator to AUTO during normal conditions (utility power present)

1. Perform required maintenance procedures. 
2. Reset the maintenance reminder light. For more information, see here: How do I clear a yellow maintenance reminder or warning on my standby generator?
3. Reinstall the intake side panel and front panel, if removed. 
4. Reinstall the 7.5A fuse in the control panel.
5. If prompted, complete the Install Wizard setup.
6. On the control panel, press the AUTO button. The display will read READY TO RUN, and the side status light will turn green.
7. Set the generator Main Line Circuit Breaker (MLCB) to ON (CLOSED). This allows the generator to send power to the house when needed.
8. Close and lock the generator's lid. 


Return the generator to AUTO during a utility outage

1. Perform required maintenance procedures. 
2. Reset the maintenance reminder light. For more information, see here: How do I clear a yellow maintenance reminder or warning on my standby generator?
3. Reinstall the intake side panel and front panel, if removed. 
4. Reinstall the 7.5A fuse in the control panel.
5. If prompted, complete the Install Wizard setup.
6. Press the AUTO button on the control panel. Allow the unit to run for one minute with no load (MLCB set to OFF). 

Note: Unless utility power is present, the generator will start its engine and run until utility power is detected.


7. Set the generator Main Line Circuit Breaker (MLCB) to ON (CLOSED). The generator will continue running until utility power returns. 

Note: in AUTO mode, once the generator detects utility power it will perform its usual shutdown process.


Additional considerations

Auxiliary shutdown (Error Code 2800): If the auxiliary shutoff switches were touched or toggled during maintenance, you may see error code 2800 on the control panel. This code indicates an auxiliary shutdown. For help resolving this, refer to the article: What Does It Mean When My Generator Displays an Error Code: Auxiliary Shutdown, Error Code 2800?

Install wizard message: If the generator battery was disconnected during service, the control panel will launch the Install Wizard once power is restored. This is normal. Follow the on-screen prompts to set the language, time, Quiet Test mode, and exercise schedule.  

Wi-Fi reconnection: If previously connected to Mobile Link, the generator may need to be reconnected after a reset or battery disconnection. For guidance, see: How Do I Reconnect My Generator to a Wi-Fi Network if It Has Become Disconnected?

See also

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