Generac Generator 1906 Error Code Explained: Meaning, Causes & Fixes

 

What the 1906 Error Code Means on a Generac Generator

 

If your Generac generator is displaying a 1906 error code, this means “Undervoltage Alarm – Shutdown.” In simple terms, the generator has detected that the electricity it is producing (specifically, the voltage) has dropped below the acceptable range for a certain amount of time. To protect your equipment and keep anyone using the power safe, the generator stops running until the problem is fixed.

 

Understanding the Basics of Undervoltage

 

Every home or business electrical system in St Louis and Nashville operates within a specific voltage range—think of voltage as electrical “pressure.” Too little pressure (low voltage) can make lights dim, cause appliances to malfunction, or even damage sensitive electronics. Generac generators closely monitor their own voltage output so they don’t supply power that could be unsafe or unreliable.

When your Generac generator detects that it’s supplying less voltage than it should for a period (often measured in seconds), it throws the 1906 code and automatically shuts off. This is a built-in safety feature designed to avoid dangerous situations and prevent further damage.

 

Possible Causes of a 1906 Undervoltage Alarm

 

• Overloaded Generator: If too many devices or large appliances are connected at once, the generator may not keep up, leading to a voltage drop.
• Engine Problems: Issues such as low oil, clogged filters, or mechanical wear can cause the engine to lose speed or run rough, which impacts voltage output.
• Faulty AVR (Automatic Voltage Regulator): The AVR is the part that controls voltage output. If it fails, the generator can’t maintain proper voltage.
• Loose or Damaged Wiring: Connections inside the generator that are loose, corroded, or damaged may cause irregular voltage delivery.
• Main Alternator Problems: If the generator’s alternator (which creates electricity) is failing, it may not be able to produce enough voltage consistently.
• Environmental Factors: Extreme cold, heat, or moisture—fairly common in both St Louis and Nashville—can contribute to electrical malfunctions.

 

Steps to Take When You See the 1906 Code

 

• Turn Off All Loads: Safely turn off or unplug all devices powered by the generator. This reduces strain and prevents further issues.
• Clear the Code: Depending on your Generac model, you might be able to clear the code by cycling the generator’s “Off” and then “On/Auto” switches. Refer to your user manual for exact instructions.
• Check Obvious Issues: Look for blown fuses, tripped breakers, visible loose wires, or excessive dirt around the generator.
• Don’t Keep Trying to Start: Avoid repeatedly restarting the generator. That can worsen problems if there’s an underlying fault.

 

When to Call a Professional

 

A 1906 code often means there’s a mechanical or electrical concern that needs an expert’s attention. If you’ve performed the basic steps above and the error keeps coming back, the issue could be with the AVR, alternator, or the internal engine—areas that are best handled by a trained generator technician. In regions like St Louis and Nashville, trained professionals can accurately assess, repair, and thoroughly test the generator to make sure it’s safe to use.

 

Regular Maintenance Tips to Prevent 1906 Errors

 

• Have your generator professionally serviced at least once a year—especially before severe weather seasons common in St Louis and Nashville.
• Keep the generator area clear of debris or snow that could affect operation.
• Test run your generator monthly (if safe to do so) to keep parts in working order.
• Do not overload circuits—only connect what the generator is rated to power.
• Address unusual noises, smells, or performance issues immediately to avoid escalation to a major fault like the 1906 error.

 

Summary

 

The 1906 error code on a Generac generator means the unit has shut itself down due to low voltage, a key safety measure. It protects your home or business in St Louis and Nashville from the dangers and inconveniences caused by unstable electricity. Common problems include overloaded circuits, engine or component failures, or electrical connections issues. After following simple troubleshooting steps, professional repair is usually necessary to fix the root cause and to prevent recurring shutdowns. Consistent preventative maintenance remains the best way to ensure your generator remains reliable whenever you need backup power.