Power outages can strike with little warning—whether from severe weather, grid failures, or unexpected technical issues. If you’re shopping for a backup generator to keep your home running during emergencies, one of the most common questions is: Will a generator start automatically when the power goes out?
The answer is: Only if your generator is equipped with an automatic transfer switch and built to support auto-start functionality. Not all generators will start automatically—but those that do can provide seamless, uninterrupted power to your home within seconds of an outage.
This guide breaks down everything homeowners need to know about automatic-start generators, including how they work, which models offer this feature, installation requirements, and whether it’s the right choice for your home backup needs.
What Is an Automatic Generator?
An automatic generator is typically a standby (permanently installed) system that starts on its own when it detects a power outage. These systems are designed to monitor your home’s power supply 24/7 and transfer power automatically from the utility grid to your generator without any manual input from you.
Key Components of an Automatic Generator System:
- Standby Generator Unit: A fixed generator powered by natural gas or propane
- Automatic Transfer Switch (ATS): Detects power failure and switches load to the generator
- Control Panel: Monitors voltage, schedules test runs, and manages generator performance
These systems are ideal for homeowners who want hands-free backup power, especially if you’re away from home often or rely on critical medical or security devices that can’t afford downtime.
Do All Generators Start Automatically?
No. Only specific types of generators—usually standby systems—can start automatically. Here’s a quick comparison of generator types and their start capabilities:
| Generator Type | Automatic Start? | Transfer Switch Required? | Best For |
|---|---|---|---|
| Standby Generator | ✅ Yes (built-in) | ✅ Yes (automatic) | Whole-home power |
| Portable Generator | ❌ No (manual start) | Optional (manual) | Short-term, partial backup |
| Inverter Generator | ❌ No (manual or electric start) | No (used with cords) | Appliance-only use, camping |
| Standby Generator with Remote Start | 🟡 Semi-auto (via app or remote) | ✅ Yes | Tech-savvy users |
Bottom Line: If you want your generator to start without you doing anything, you need a standby generator with an automatic transfer switch.
How Do Automatic Generators Work?
Automatic standby generators operate through a seamless process involving real-time power monitoring. Here’s how it works step-by-step:
Step 1: Utility Power Is Lost
The system continuously monitors the utility power coming into your home. The moment it detects a power interruption, it activates.
Step 2: Transfer Switch Engages
The automatic transfer switch (ATS) disconnects your home from the grid to prevent backfeeding and routes power from the generator instead.
Step 3: Generator Starts Automatically
The generator engine fires up—usually within 10 to 30 seconds—and begins delivering power to the designated circuits or entire house.
Step 4: Power Is Restored
Once utility power is restored, the ATS switches back to grid power and shuts off the generator after a short cool-down period.
This entire process happens without any manual intervention—even if you’re away from home.
What Is an Automatic Transfer Switch (ATS)?
An automatic transfer switch is the heart of any auto-start generator system. It’s a device that instantly detects power loss and safely switches the electrical load from the utility to the generator—then back again when power is restored.
Benefits of an ATS:
- Fast, seamless transfer of power
- Eliminates manual startup/shutdown
- Improves safety by avoiding backfeeding
- Works with whole-house or selected circuit coverage
Most standby generator packages include an ATS pre-configured for your home’s size and power needs. Proper installation is required by a licensed electrician to ensure code compliance and safety.
Can Portable Generators Start Automatically?
No, traditional portable generators cannot start automatically when the power goes out. They require you to:
- Manually start the engine (pull-start or electric button)
- Connect the generator to a transfer switch or extension cords
- Switch over power manually (if using a transfer switch)
While some high-end portable models include remote or electric start capabilities, they still require human input. There is currently no reliable system that fully automates portable generator use in the same way standby systems do.
Is an Automatic Generator Worth the Investment?
If you live in an area with frequent outages, have essential appliances or medical equipment, or want true peace of mind during storms, then yes—an automatic-start generator is absolutely worth it.
✔️ Advantages of Automatic Generators:
- Power is restored within seconds of an outage
- No need to be home to activate the system
- Protects perishable food, HVAC systems, and critical electronics
- Hands-free operation for families with seniors or young children
- Boosts home value and energy resilience
While automatic standby systems cost more upfront (typically $5,000–$15,000 installed), they provide unmatched reliability and protection.
Installation Requirements for Automatic Generators
Because automatic generators integrate with your home’s electrical and gas systems, professional installation is mandatory. Here’s what’s involved:
Installation Checklist:
- Generator unit placement (minimum 5 feet from openings per code)
- ATS installation near your electrical panel
- Connection to a fuel source (natural gas or propane)
- Electrical load calculation and circuit configuration
- Permits and local code compliance
- Startup testing and inspection
Once installed, the system runs periodic self-tests (usually weekly) to ensure it’s ready for the next outage. Annual professional maintenance is also recommended.
Top Automatic Generator Brands
If you’re in the market for a generator that starts automatically, here are some top-rated standby options:
🔌 Generac Guardian Series (22kW)
- Runs on natural gas or propane
- Includes automatic transfer switch
- Whole-home coverage for medium to large homes
💡 Kohler 20RESCL-200SELS
- Premium 20kW standby generator with ATS
- Extremely quiet and reliable
- Ideal for sensitive electronics and HVAC systems
🔥 Champion 14kW Home Standby System
- Affordable standby option with ATS
- Weather-resistant housing
- Great for small to medium homes
FAQs About Automatic-Start Generators
Q: How long does it take for a generator to start after a power outage?
Most standby generators start within 10 to 30 seconds of detecting an outage, depending on the model and installation.
Q: Can I use a remote or app to start my generator?
Some newer models allow app-based or remote start options, but these still require manual confirmation unless paired with an ATS. Fully automatic operation only comes with standby systems.
Q: Can I convert my portable generator to start automatically?
Not reliably. Some DIY hacks exist, but they’re unsafe and not code compliant. Only standby systems are designed for automatic starting and safe integration with home power systems.
Q: Do automatic generators require maintenance?
Yes. Even if rarely used, standby generators require annual maintenance, including oil changes, filter replacements, and testing to ensure they’re ready when needed.
Q: Will a generator keep running until power is restored?
Yes. Once the ATS transfers your home to generator power, it continues to run until grid power is restored—then automatically switches back and powers down the generator.
Conclusion: Want Seamless Backup Power? Choose an Automatic Generator
If you want true peace of mind during a power outage, only a standby generator with automatic start capability can deliver seamless protection. Within seconds of losing grid power, your system will start automatically and restore essential functions—keeping your home safe, comfortable, and connected.
While portable generators serve a purpose, they require manual operation and are not designed for automatic failover. If convenience, reliability, and whole-home protection are priorities, investing in an automatic-start standby generator is the smartest solution.
Still Deciding Which Generator Is Right for You?
Check out our expert guide: What Size Generator Do I Need for My Home? to learn how to size, fuel, and configure the perfect generator system for your home’s emergency needs.