Generac Lights and Alarms: What Each Light Means and How to Clear It

What each Generac light means, by controller

Find your generator's line below and read the light as Generac's own manual defines it. The same colour can mean different things on different controllers: red is both OFF and alarm on every line, and only the Next Generation manual separates solid from flashing for every light. Meanings are quoted; the source column gives the document and page.

More than one light can be on at once. The Guardian and Next Generation manuals say the yellow light "may be illuminated at the same time as either the red or green LED"; the 2016 manual says the "Yellow Maintenance or Warning LED may be on at the same time as either the Red or Green LED"; and the Next Generation manual adds that the blue light "may be illuminated at the same time as any other LED." Generac's lights article warns that "Certain combinations (like red and yellow together) can be confused with an orange status." On a PowerPact, the starred LEDs are shared: "Solid light indicates one alarm. Flashing light indicates the other alarm condition."

Not in the table, because no Generac document we could reach defines it: the lights on Nexus-controller units (Generac no longer hosts a Nexus owner's manual, and its lights article covers only Next Generation and Guardian units from 2017), and the Honeywell-branded Sync controllers.

Alarm, warning or maintenance reminder: which one is it?

Generac sorts every message into three kinds. Red is an alarm, and the generator will not run. Yellow is a maintenance reminder or a warning, and the generator still runs. The difference matters when you clear it: a reminder clears once you log the service, while a warning clears only when its cause is fixed.

All rows are from Generac's article What is the difference between maintenance reminders, warnings, and alarms? (Jan 30, 2026). It adds two notes worth having: "Guardian series generators will display a solid YELLOW light. Next Generation series generators will display a flashing YELLOW light," and "A solid RED light also appears when the generator is OFF, which can be mistaken for an alarm." The same article calls alarms "a solid RED light", while the Next Generation manual (p. 20) describes a solid red light as OFF and a red light flashing at one-second intervals as a fault.

How to clear an alarm on a Generac

Deal with the cause first, then clear the alarm and test with a MANUAL start. Evolution and Sync: OFF, then ENTER, then AUTO. Next Generation: hold OFF for at least three seconds, then AUTO. Nexus and PowerPact have their own sequences, below. If the alarm returns, Generac says to call a dealer.

Each code page on this site says what has to be true before its alarm will clear. The button sequences themselves are the same for every code, so they are kept here.

Guardian series: Evolution and Sync controllers

From Generac's article How Do I Clear an Error or Alarm Code On My Home Standby Generator? (Feb 19, 2026):

1. "Locate the external switch on the back side of the generator."
2. "Ensure the Switch is in the I or Closed position."
3. "If applicable, locate the internal switch on the inside panel of the generator." Generac's note: "This step is only for 13KW generators or larger."
4. "Go to the front of the generator, lift the lid, and locate the Controller on the top right side of the generator."
5. "As instructed by the controller display, in order, press the red OFF button, then the ENTER button."
6. "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)."
7. "If the alarm returns after setting the unit to AUTO, contact a Generac authorized service dealer for help."

The owner's manual gives it in one line (A0001846499 Rev. C, Quick Reference Guide, p. 34): "To clear an active alarm, press OFF button on the control panel, then the ENTER button, and finally the AUTO button. Contact an air-cooled certified IASD if alarm reoccurs." Some of Generac's code articles, for 1300 and 1600 among them, write the sequence as "Press OFF, ENTER twice, then AUTO." The general article's wording covers both: press the buttons "As instructed by the controller display."

Next Generation series: Power Zone 200 controller

From the same article:

1. "To clear an alarm code on a Next Generation Series generator with a Power Zone 200 controller, hold the OFF button for at least three seconds. The red LED will become solid when the alarm is cleared."
2. "To return the generator to service, or 'ready to run', press the AUTO button on the control panel."
3. "If the alarm returns after setting the unit to AUTO, contact a Generac authorized service dealer for help."

The Next Generation owner's manual (A0004332577 Rev. C, Quick Reference Guide, p. 37): "Press and hold OFF button for at least 3 seconds to clear an active alarm. Red OFF mode LED will become solid when the alarm is cleared. Contact an air-cooled certified IASD if alarm reoccurs."

Nexus controllers

From the same article:

1. "Move the rocker switch to OFF."
2. "Press Enter twice."
3. "Move the rocker switch back to AUTO."
4. "If the alarm returns after setting the unit to AUTO, contact a Generac authorized service dealer for help."

For units without the rocker: "press the OFF button, then press enter twice to clear an alarm code."

PowerPact 7.5 kW

Generac's article: "For the 7.5kW PowerPact unit press the OFF button twice to clear an active alarm or maintenance/warning. If an active alarm and maintenance/warning are present at the same time, press the OFF button 3 times to clear." The PowerPact manual (10000021790 Rev. C, p. 15) says the same — "Press OFF button to clear an alarm or warning condition from control panel. Press OFF button again to turn off flashing or solid indicator LED." — and adds the warning that applies to every Generac: "Clearing a code will not correct the problem. It will simply turn off the LED indicating a problem occurred. The problem indicated must be diagnosed and corrected to prevent a re-occurring alarm condition."

Clearing from Mobile Link

Generac's documents disagree on this. The clearing article says "Users with a Premium Mobile Link subscription can clear maintenance reminders but not warnings or alarms using Mobile Link." The Mobile Link dismissal article (Apr 9, 2026) says a Premium subscriber can dismiss a maintenance reminder or a warning, and that "Currently only Evolution 2, Sync 3.0, and PowerZone 200 controllers support dismissing warnings within the Mobile Link app with a paid subscription." Neither one says an alarm can be cleared from the app.

How to clear the maintenance reminder (yellow light)

Do the service first; the reminder runs on a timer, not a measurement. Guardian: press ENTER while it is showing and confirm YES. Next Generation: select "Clear Maintenance" in Mobile Link, or hold OFF for three seconds and press AUTO. PowerPact: press OFF twice, or three times if an alarm is also showing.

Guardian series: Evolution I, Evolution II and Sync 2.0

From Generac's article Understanding yellow maintenance reminder and warning lights (Oct 2, 2025):

1. "On the control panel when the maintenance reminder is displayed, press ENTER."
2. "Service performed? using the up/down arrows near the enter button, toggle YES and press ENTER."

The owner's manual's Quick Reference Guide (A0001846499 Rev. C, p. 35) gives the same instruction per reminder: SERVICE A, "Perform SERVICE A maintenance. Press ENTER to clear."; SERVICE B, "Perform SERVICE B maintenance. Press ENTER to clear."; INSPECT BATTERY, "Inspect battery. Press ENTER to clear." Generac's Inspect Battery article words it differently for Evolution controllers: "Press OFF, ENTER twice, then AUTO."

Next Generation series: Power Zone 200

From the same yellow-light article: "On the control panel, hold OFF for three seconds. Then, to return the generator to automatic mode, press the AUTO button on the control panel." Or, in Mobile Link: "Select Clear Maintenance," then "Confirm the generator is back in AUTO and showing a green light." The Next Generation manual's Quick Reference Guide (p. 39) uses the app route for each reminder: "Perform SERVICE A maintenance. Select 'Clear Maintenance' in app to clear." (and the same for SERVICE B and SERVICE C), and "Inspect battery. Select 'Clear Maintenance' in app to clear."

PowerPact 7.5 kW

The manual's table (10000021790 Rev. C, p. 15): to clear a maintenance LED, "Press OFF", then "Press OFF again"; to clear a maintenance LED "when Alarm or Warning LED is also present", press OFF a third time.

A yellow warning, not a reminder

A warning does not clear from a key press until its cause is gone. The yellow-light article: "Correct the cause of the underlying warning (LOW BATTERY, BATTERY PROBLEM, CHARGER WARNING, CHARGER MISSING AC)." For Guardian units it then gives "press OFF, press ENTER, press ENTER again" and AUTO; for Next Generation units, "The yellow warning light will clear itself when the underlying issue is resolved."

What "Charger Missing AC" means

Charger Missing AC, code 2780, is a yellow warning: the controller is not seeing 120 V on the T1 wire that feeds its battery charger. During an outage it can mean the generator's main breaker is off or the transfer switch did not move. With the utility on, suspect the T1 fuse or wiring: a technician's check.

Generac's 2780 article (Sep 21, 2026) gives the meaning as: "Code 2780 normally indicates that the controller is not detecting the expected 120 VAC on the T1 battery charging circuit. This may be caused by an issue with the T1 wire or T1 fuse." What it lets an owner check depends on whether the grid is up:

• During an outage, with the generator running: "Charger Missing AC may occur if the automatic transfer switch did not transfer to generator power or the generator main line circuit breaker (MLCB) is not set to ON. Check that the MLCB is set to ON." Generac's starting-issues article adds that "'Charger Missing AC' warnings are expected during outages and are not indicative of charger faults."
• With utility power on: "A qualified technician can use a multimeter to confirm the voltage received on the T1 wire," and "can inspect the T1 fuse inside the transfer switch". The article's warning: "Generac does not recommend end users attempt to modify or service internal generator wiring or attempt to service the transfer switch."
• On a new installation: Generac's installation article notes that some jurisdictions require a separate neutral for the charger circuit and that "Charger missing AC is displayed when 120 volts is not present on T1, which will happen if the T1 fuse is blown or during an outage if the generator is not running." Wiring is the installer's to correct.
• On some Next Generation units: the article says a limited number "may display Charger Missing AC code 2780 even when the generator is operating normally and the battery charger is maintaining the battery." It names the conditions a technician confirms before treating it as a nuisance warning, the first being "The battery voltage is greater than 12.1 VDC," and says such a unit "should continue to exercise and operate during an outage."

Both owner's manuals give the same one-word answer in their Quick Reference Guides: CHARGER MISSING AC, "Contact an IASD." (A0001846499 Rev. C, p. 35; A0004332577 Rev. C, p. 38). The warning clears by itself once T1 has power again: "code 2780 should clear automatically after the underlying issue is corrected." The full page, with the three related battery and charger codes, is Generac code 2780.

If it won't clear or comes back

A code that returns after AUTO, or will not clear at all, is Generac's signal to stop resetting it and call a dealer, leaving the code on the unit for the technician. A hard reset, which cuts all power to the controller, is documented for an alarm that will not clear, but Generac says most codes never need one.

What Generac's documents say, in their words:

• Clearing article: "If the alarm returns after setting the unit to AUTO, contact a Generac authorized service dealer for help."
• Generac's code articles, for example the RPM Sensor Loss and Low Oil Pressure articles, on working with a dealer: "Leave the error code present on the unit so it can be properly diagnosed."
• Mobile Link dismissal article: "If the maintenance reminder or warning returns after addressing the issue and dismissing or clearing the notification, this indicates that there is an issue with the generator that has not been resolved."
• Hard reset article (Mar 2, 2026): "Error codes usually do not require a hard reset to clear." It lists "An alarm that does not clear" among the symptoms a hard reset may resolve, and warns that "This process may power off all devices in your home when flipping the main disconnect switch." The procedure removes the controller fuse, disconnects the battery and turns off the home's service disconnect; it is not reproduced here, and Generac's own advice if you are not comfortable with it is a certified technician.

The codes that most often bring people here, each with what has to be true before it clears: 1100 overcrank, 1300 low oil pressure, 1505 RPM sense loss, 2100 overload and 2800 shutdown switch. Next Generation codes, which show only in Mobile Link, are on the Next Generation code list; every other code is on the Generac error code hub.