Your Kohler generator is in Manual mode and will not start automatically when the power goes out—you need to switch it to Auto mode on the controller.
What “Not in Auto” Means
The “Not in Auto” warning on a Kohler RDC2 controller tells you that your generator is currently set to Manual mode instead of Automatic (standby) mode. When your generator is in Manual mode, it ignores all remote start and stop commands from your transfer switch or remote control. Most importantly, it will not detect a power outage and start on its own—you’d have to manually start it by pressing a button on the controller itself.
For a home standby generator, this is a critical distinction. The whole point of having a standby system is that it springs to life automatically when utility power fails, keeping your home running without any action from you. If your generator is stuck in Manual mode, that automatic protection disappears.
Why Your Generator Is in Manual Mode
Kohler RDC2 controllers default to Manual mode for safety reasons. This prevents accidental starts during maintenance, testing, or installation. Common reasons your generator is in Manual mode include:
- Recent installation or service: A technician may have left it in Manual mode after work.
- Power loss to the controller: If the backup battery in the controller dies or loses charge, the system may revert to Manual mode.
- You switched it yourself: You or someone else may have accidentally pressed the Manual button during operation or testing.
- System reset: A power surge or electrical fault can reset the controller to its default state.
Diagnostic Checklist
- Check the controller display. Look at your RDC2 controller panel. You should see an indicator showing either “AUTO” or “MANUAL.” If it says “MANUAL” or you see the “Not in Auto” warning message, proceed to the next step.
- Locate the AUTO button. On the RDC2 controller, find the button labeled “AUTO.” It’s typically a large, clearly marked button on the front panel. Refer to your owner’s manual if you’re unsure which button it is.
- Press the AUTO button. Press and hold the AUTO button for 2–3 seconds until you see the display change to show “AUTO” mode. You may hear a relay click or see an indicator light change. This is normal.
- Verify the mode change. Check the controller display to confirm it now shows “AUTO” or “AUTOMATIC.” The “Not in Auto” warning should disappear.
- Test the transfer switch (optional). If your generator is connected to a transfer switch, you can verify the system is now responsive by checking that the transfer switch can communicate with the generator. Consult your transfer switch manual for testing instructions—do not simulate a power outage by cutting utility power yourself.
- Check the backup battery. If the controller keeps reverting to Manual mode, the backup battery inside the RDC2 may be weak or dead. Look for a small battery compartment on the controller (usually on the back or side). If the battery appears corroded or is more than 3–5 years old, it may need replacement.
- Review recent service history. If a technician recently serviced your generator, contact them to confirm they switched the system back to Auto mode before leaving.
When to Call a Pro
Contact a qualified Kohler service technician if:
- The controller will not switch to Auto mode no matter how many times you press the button.
- The “Not in Auto” warning returns repeatedly even after you switch to Auto mode.
- The controller display is blank, flickering, or showing error codes other than “Not in Auto.”
- You hear no relay click or see no indicator light change when pressing the AUTO button.
- The backup battery compartment shows visible corrosion or leakage.
- Your generator is under warranty and you’re unsure whether DIY troubleshooting is appropriate.
Parts You May Need
- RDC2 controller backup battery (if the battery is dead or dying)
- Replacement RDC2 controller (if the controller itself is faulty)
Frequently Asked Questions
Can I run my generator in Manual mode if I’m home to start it myself?
Technically, yes—you can manually start a generator in Manual mode by pressing the start button on the controller. However, this defeats the purpose of a standby system. If you’re away from home or asleep during a power outage, you won’t be there to start it. Standby generators are designed to operate in Auto mode so they respond to utility power loss automatically, 24/7.
How often should I check that my generator is in Auto mode?
Check the controller display at least once a month as part of routine maintenance. A quick glance at the panel takes only a few seconds and gives you peace of mind that your system will respond if the power goes out. Some homeowners set a monthly reminder on their phone to make this a habit.
What happens if the power goes out while my generator is in Manual mode?
Nothing. Your generator will not start. The RDC2 controller will not detect the outage and will not send a start command to the engine. Your home will lose power just as if you didn’t have a generator. This is why the “Not in Auto” warning exists—it’s a safety alert telling you that your backup system is offline.
Will switching to Auto mode start my generator immediately?
No. Switching to Auto mode simply enables the system to respond to a power outage or remote commands. It does not start the engine. The generator will only start when it detects that utility power has been lost (or when you manually press the start button). This is the correct behavior.
Disclaimer
This article provides general information about Kohler RDC2 controllers and the “Not in Auto” warning. It is not a substitute for your generator’s owner’s manual or professional service. Always consult the manufacturer’s manual for your specific model before performing any maintenance or troubleshooting. If you are unsure about any step, contact a qualified Kohler service technician. Improper operation or maintenance of a generator can result in injury, property damage, or equipment failure.
Source: Information adapted from official manufacturer documentation (reference). Always consult your generator owner’s manual for model-specific procedures.