Knowing how to use a generator the right way keeps the lights on during an outage and, more importantly, keeps your family safe from the hidden dangers that send thousands of people to the hospital every year. A portable generator is an engine-powered machine that produces electricity you can use to run appliances, tools, and lights when grid power is unavailable. Used correctly, it is a lifeline during storms and a handy power source for camping or job sites. Used carelessly, it can cause deadly carbon monoxide poisoning, electrical shock, or fire. This guide walks you through every step, from setup to safe shutdown.
Quick answer: To use a generator, place it outdoors at least 20 feet from your home with the exhaust pointing away, add fuel and oil, then start it before plugging anything in. Connect devices with heavy-duty outdoor extension cords, or use a professionally installed transfer switch, and never plug a generator directly into a wall outlet.
Key takeaways
- Always run a generator outdoors, at least 20 feet from windows, doors, and vents, with the exhaust directed away from the house.
- Start the generator first, let it stabilize, then connect your loads one at a time to avoid overloading it.
- Never plug a generator into a wall outlet. This dangerous practice, called backfeeding, can electrocute utility workers and start fires.
- Add up the running and starting watts of everything you plan to run so you never exceed the generator’s rated capacity.
- Turn the engine off and let it cool before refueling, and install carbon monoxide alarms on every level of your home.
Why does using a generator safely matter?
A generator burns gasoline, propane, or diesel, and that combustion produces carbon monoxide (CO), an invisible, odorless gas that can kill in minutes. CO is the single biggest hazard of generator use, and it builds up fast in garages, sheds, and even open porches close to the house. Opening a window or running a fan does not clear it. That is why placement is not a suggestion but a life-or-death rule.
Beyond CO, generators carry real risks of electrical shock and fire. According to the Electrical Safety Foundation International generator safety guidance, you should keep the unit dry, never refuel a hot engine, and only connect it to your home through a transfer switch installed by a licensed electrician. Respect these rules and a generator becomes one of the most reliable tools you own.
Generator types and key terms explained
Before you start, it helps to know what you are working with. Running watts (also called rated watts) is the continuous power a generator supplies, while starting watts (surge watts) is the extra burst it can deliver for a few seconds when a motor, like a fridge compressor, kicks on. Sizing your generator means matching both numbers to your loads.
| Type | Best for | Notes |
|---|---|---|
| Portable | Home backup, job sites, tailgating | Affordable and powerful, but louder and needs manual setup |
| Inverter | Camping, electronics, RVs | Quiet and fuel-efficient with clean, stable power for sensitive devices |
| Standby | Whole-house automatic backup | Permanently installed, starts automatically, higher cost |
For most homeowners riding out a storm, a portable or inverter model in the 3,500 to 7,500 watt range covers the essentials. Match the machine to your real needs before you buy, and always check the outlets it offers.
What you need before you start
- Fuel and oil: fresh fuel of the correct type, plus the oil your manual specifies. New generators often ship without oil.
- Heavy-duty outdoor extension cords: rated for the wattage you will draw, in good condition with no cuts or exposed wire.
- A dry, level spot outdoors: at least 20 feet from the house, protected from rain by an open canopy but never enclosed.
- Carbon monoxide alarms: working, battery-backed CO detectors on every level of your home.
- A transfer switch (optional but recommended): for powering hardwired circuits, installed by a licensed electrician.
Do this prep before the storm hits, not during it. Fuel sells out fast, and setting up a generator in the dark and rain is exactly when mistakes happen.
How to use a generator step by step
- Position the generator outdoors. Place it on a dry, level surface at least 20 feet from any window, door, or vent, with the exhaust pointing away from the house.
- Check oil and fuel. Confirm the oil is at the correct level and add the right fuel. Wipe up any spills before starting.
- Make sure nothing is plugged in. Start the generator with no load attached so it can come up to speed safely.
- Start the engine. Set the fuel valve and choke as your manual directs, then pull the recoil cord or press the electric start button.
- Let it warm up. Give the engine a minute or two to stabilize its output before you connect anything.
- Connect your loads one at a time. Plug in devices using outdoor-rated cords, starting with the largest, and add the rest gradually so you do not overload it.
- Monitor as it runs. Watch that you stay within the wattage rating, keep the area clear, and check for any warning lights or unusual sounds.
- Shut down safely. Unplug all devices, then turn the generator off. Let it cool fully before refueling or storing it.
How do you connect a generator to your house safely?
There are two safe ways to power your home. The simplest is running heavy-duty outdoor extension cords from the generator directly to individual appliances. The better option for whole-circuit power is a manual transfer switch, a device a licensed electrician wires into your electrical panel. It isolates your home from the utility grid so your generator can safely feed hardwired circuits like the furnace or well pump.
What you must never do is plug the generator into a wall outlet to power the house. This shortcut, known as backfeeding, sends electricity backward through your wiring and out to the power lines, where it can electrocute utility workers and cause a fire when grid power returns. There is no safe version of backfeeding, so always use a transfer switch or extension cords.
How much can your generator power?
To size your needs, add up the running watts of everything you want to power, then add the highest single starting-watt figure among them. These are typical estimates, so always check the labels on your own appliances:
| Appliance | Running watts | Starting watts |
|---|---|---|
| Refrigerator | 600 to 800 | 1,200 to 2,200 |
| Sump pump | 800 to 1,050 | 1,300 to 3,000 |
| Portable heater | 1,500 | 0 |
| Lights and phone chargers | 200 to 400 | 0 |
| Window air conditioner | 1,000 to 1,500 | 2,200 to 3,000 |
Add a comfortable margin above your total so the generator is never running flat out. Overloading causes overheating, trips the breaker, and shortens the machine’s life.
Common generator problems and how to fix them
- Will not start: check the fuel level, oil level, and choke position. Many generators have a low-oil sensor that blocks starting until you add oil.
- Runs but no power at the outlets: a tripped circuit breaker or loss of residual magnetism is common. Reset the breaker and consult your manual on flashing the field.
- Stalls under load: you are likely drawing too many watts. Unplug the largest device and reconnect loads more gradually.
- Hard starting after storage: stale fuel is usually the culprit. Drain old fuel, add fresh, and use a stabilizer for next time.
Choosing the right generator for your needs
The safest, smoothest experience starts with the right machine for the job. For reliable storm backup, our guide to the best generators for the home compares the top picks for running essentials, while our roundup of the best portable generators for home focuses on models that balance power and portability.
If you want to run your entire house, see our picks for the best generators for whole house coverage. For smaller needs, the best 2000-watt generators are perfect for lights and electronics, and campers will want a quiet unit from our best portable generators for camping guide. A generator can even power corded outdoor tools, so once the storm passes you can get right back to jobs like using a pressure washer to clean up the mess.
Frequently asked questions
How far from the house should a generator be?
Place a generator at least 20 feet from your home, with the exhaust pointing away from any window, door, or vent. Never run it in a garage, shed, basement, or covered porch, even with the door open. Carbon monoxide builds up quickly in these spaces and can be deadly.
Can you plug a generator into a wall socket?
No, never plug a generator into a wall outlet. This practice, called backfeeding, pushes power backward through your home wiring and out to the grid, where it can electrocute utility workers and start a fire. Use extension cords or a licensed electrician-installed transfer switch instead.
Can you refuel a generator while it is running?
No, always turn the generator off and let it cool before refueling. Gasoline spilled on a hot engine or exhaust can ignite instantly. Keep fuel stored in approved containers well away from the running generator and any ignition source.
What size generator do I need to run my house?
For essentials like a fridge, sump pump, and lights, a 3,500 to 5,000 watt generator is usually enough. To run most of a typical home, including central air, you often need 7,500 watts or more. Add up your running and starting watts to be sure.
Can a generator run in the rain?
Not without protection. Water and electricity are a dangerous mix, so never operate a generator in wet conditions unless it is shielded by an open, well-ventilated canopy or a purpose-built generator tent. Keep the unit dry and elevated, and make sure air can still flow freely around it.
Final thoughts
Once you know how to use a generator safely, you gain real peace of mind that your home stays powered when the grid goes down. Keep the core rules front of mind: run it far outdoors with the exhaust aimed away, start it before connecting loads, never backfeed a wall outlet, and let it cool before refueling. Follow those habits and your generator will deliver reliable power for years. When you are ready to buy or upgrade, start with our tested picks for the best generators for the home and match the wattage to what you truly need.