I've been running portable generators for the better part of a decade, mostly for backup at home and for work out in the open, cutting wood at the treeline and running power tools where there's no outlet for miles. In all that time, the machine itself has almost never been the thing that worried me. What people get wrong is how they run it. So before any of the how-to, let me walk you through the handful of safety rules I take seriously every single time, because these are the ones that actually keep people alive.
Carbon monoxide is the danger, not the machine
If you remember one thing from this whole page, make it this. A running generator puts out carbon monoxide in its exhaust, and carbon monoxide gives you no warning at all. You can't see it, you can't smell it, and by the time you feel dizzy or sick it's already working on you. That's what makes it so dangerous compared to the things people usually worry about.
The rule I never bend is simple: the generator runs outside, out in the open air, and nowhere else. Not in the garage, not in the basement, not in a shed, not under the eaves by an open window, not in the bed of a truck with a topper on it. I don't care if it's raining or if it's just for a few minutes. Every year people die because they ran one in an attached garage 'just this once,' and the fumes found their way inside. There's no version of indoors that's safe, and I won't pretend otherwise.
Where I put it, and which way it faces
Distance and direction both matter. The manual gives you a minimum operating clearance of about one meter, roughly three feet, from the building and anything around it. I treat that as the floor, not the target. The guidance I actually follow comes from the CDC and CPSC: keep it at least twenty feet, about six meters, from the house, and point the exhaust away from it.
Twenty feet sounds like a lot until you've watched exhaust drift back toward an open window on a still day. Give yourself the room. And think about your neighbors too, if you're close together, your exhaust is their air. Aim it at open space, away from doors, windows, and any vent that breathes into a living area.
One more layer worth having: a battery-powered carbon monoxide alarm inside any building where people are. Every model in this lineup also has a built-in CO detection and auto-shutoff system that kills the engine if it senses dangerous levels, which is a genuinely good backstop, but I still want an alarm indoors too. A backstop is not a license to get careless. Learn more
Refueling: cool it down first, every time
Gasoline and a hot engine are a bad combination, and this is where impatience gets people burned. I shut the engine off and let it cool before I put fuel anywhere near it. Fuel splashed onto a hot muffler can flash, and it happens faster than you'd think.
No smoking, no open flame, nothing that sparks while you're near the fuel. I don't top it off to the very brim either, gasoline expands, and an overfilled tank weeps fuel onto the neck. If I spill any, I wipe it up and let it dry before I restart. None of this takes more than a couple of extra minutes, and those minutes are cheap insurance.
Never backfeed your house. I mean never.
This is the one that makes me wince when I hear people brag about it. Backfeeding means running a cord from the generator into a regular wall outlet to push power back into your home's wiring. People do it because it seems clever and it saves buying proper equipment. It's also one of the most dangerous things you can do with a generator.
When you backfeed, you energize your home's wiring without any isolation from the utility line. That can send power back down the lines and electrocute a utility worker who thinks the circuit is dead. It can start a fire. And the homemade 'male-to-male' cords people build for this have live, exposed prongs, which is exactly as bad as it sounds. There is no safe way to do it.
If you want the generator tied into your house circuits, the right way is a transfer switch installed by a licensed electrician. It isolates your home from the grid and does the job safely. Pay for it once and never think about it again. There's more on safe startup and shutdown in How to Start a Portable Generator Safely.
Wet weather, and a few smaller habits
Electricity and water don't forgive mistakes. I keep the generator dry and on dry, level ground, and I don't operate it with wet hands or standing in water. If a unit has been sitting outside exposed to weather, I check the control panel and connections before I start it, because moisture or ice in the wrong place causes trouble.
The small stuff rounds it out: keep it level so fuel doesn't slosh out, keep kids and pets away from it while it's running, know where the shutoff is before you need it, and leave the safety sensors alone. Those sensors, the CO shutoff, the low-oil cutoff, the overload protection, are there to save you and the machine. I've never once wished I'd bypassed one.
The rules I keep by the machine
If you want the short version to tape to the wall, here's what it comes down to:
| Outdoors only | Carbon monoxide is invisible and deadly, never run it enclosed. |
|---|---|
| 20 ft, exhaust away | Keeps fumes out of living space; the manual's 1 m is only the floor. |
| CO alarm indoors | Plus the built-in shutoff, two layers, not one. |
| Cool before fuel | Fuel on a hot engine can flash. |
| Never backfeed | Use a transfer switch; protects you and utility workers. |
| Dry and level | Prevents shock and fuel spills. |
| Leave sensors alone | They protect your life and the engine. |
Questions people ask
Can I run it in the garage if I leave the door open?
No. An open door does not clear carbon monoxide, and an attached garage shares air with the house. Outdoors only, well away from the building.
How far from the house is far enough?
The manual sets a one-meter minimum clearance, but follow the CDC/CPSC guidance of at least twenty feet, with the exhaust pointed away from the house.
Isn't the built-in CO shutoff enough on its own?
It's a strong backstop, but treat it as a second layer. Still place the generator correctly and keep a CO alarm indoors.
Why is backfeeding such a big deal?
It energizes your wiring without isolating it from the grid, which can electrocute utility workers and cause fires. Use a transfer switch installed by an electrician instead.
Can I refuel while it's running to avoid downtime?
No. Shut it off and let it cool first. Fuel near a hot engine can ignite.
Last updated: July 3, 2026 · Reviewed by: SIOKIUU Power Support