Skill guide · Energy & Heat

Generator, Heater & Utility Shutoff Safety

Three separate skills that all live in the Energy & Heat chapter and its addendum: running a generator without becoming one of the roughly 100 people who die every year from doing it wrong, knowing why an indoor propane or kerosene heater carries the same kind of risk, and knowing how to shut off your home's gas, water, and electricity before you actually need to. Building a fire you can actually count on has moved to its own guide, Fire-Starting: Ignition, Fire Lays & Extinguishing.

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Smell gas, or hear it hissing? Leave the house immediately, on foot. Don't touch light switches or anything electrical on your way out. Shut off the valve from outside only if you can do it safely without going back in.

Earthquake damage, sparking, or a burning smell? Shut off power at the main breaker.

Someone near a running generator or heater has a headache, dizziness, nausea, or confusion? Get everyone into fresh air immediately and call 911.

Running a generator without it killing you

This isn't an exaggeration for effect. The CDC attributes more than 400 U.S. deaths a year to carbon monoxide poisoning, and the Consumer Product Safety Commission puts the number specifically tied to portable generators at close to 100 a year, most of them after storms, when a generator is exactly the tool people reach for. Carbon monoxide is colorless and odorless; by the time you notice symptoms, you're already being poisoned.

Infants, pregnant women, older adults, and anyone with heart or lung disease are especially vulnerable, sick at concentrations too low to seriously affect a healthy adult. A fetus is at particular risk since fetal blood cells bind CO even more readily than an adult's do. If anyone like this is in the home, treat the earliest symptoms and the smallest suspected exposure as urgent, rather than waiting to see if it gets worse.

What CO poisoning actually feels like, since knowing the symptoms is what makes 'catch it early' possible

Headache, dizziness, weakness, nausea, and confusion, often described as feeling like the flu, are the early warning signs; the danger is exactly that they're easy to write off as something else while a generator or unvented heater is running nearby. Anyone asleep or impaired by alcohol or other substances can be poisoned before ever waking up to notice. If anyone in the home develops these symptoms while a generator or fuel-burning heater is in use, get everyone into fresh air immediately and call 911 before trying to figure out the cause; don't wait to see if it passes.

Warning

The rules that actually prevent deaths

Never run a generator indoors, not in a house, garage, basement, crawlspace, or shed, even with doors and windows open. Opening a window does not provide enough ventilation to prevent lethal CO buildup.

Never run it on a porch or in a carport either. Both are common mistakes and both are too close to the home.

Keep it at least 20 feet from your home, with the exhaust pointed away from windows, doors, and vents, even ones that are currently closed. A portable generator produces roughly as much carbon monoxide as hundreds of cars, and it can linger in and around a home for hours after the generator has been shut off.

Install carbon monoxide detectors with battery backup on every level of your home, so they still work if the utility power (not your generator) is out. Where to find it: any hardware store or general retailer; look for UL listing on the package.

Watch it: U.S. Consumer Product Safety Commission, "CPSC PSA: One portable generator produces the same amount of Carbon Monoxide as hundreds of cars".

Never backfeed your house

Warning

Backfeeding kills lineworkers, not just a theoretical risk

Plugging a generator into a regular wall outlet with a double-male "suicide cord" to power your house's circuits from the outside in, called backfeeding, is illegal in every U.S. jurisdiction and has directly killed utility workers. The power doesn't stay in your house: it travels back through your breaker panel to the transformer outside, which steps it back up to line voltage and can energize the entire neighborhood's utility lines, including for a lineworker who has every reason to believe those lines are dead while repairing the outage your generator is now feeding power into.

The legal, safe alternative is a transfer switch (manual or automatic), which physically isolates your home's wiring from the utility grid before your generator's power can reach it, making backfeeding impossible by design. An interlock kit on your breaker panel does the same job at lower cost. Where to find it: transfer switches and interlock kits are sold at hardware and electrical supply stores and online, but installation belongs to a licensed electrician; this is not a DIY wiring project given what's actually at stake.

Basic safe operation

RuleWhy
Let the engine cool before refueling Spilled gasoline on a hot engine or muffler can ignite instantly
Keep the generator dry and on a dry surface Operating it wet risks electrocution
Don't overload it Check the generator's rated wattage against your total load; overloading damages the generator and connected appliances and is itself a fire risk
Store fuel outside the home, in approved containers Gasoline vapor is itself a fire and health hazard indoors

See Sizing a Fuel-Powered Generator for the actual sizing math behind "check the generator's rated wattage against your total load," real fuel consumption by type, and why an inverter generator matters if a CPAP or other medical electronics are in the picture.

Indoor propane and kerosene heaters carry the same risk

When a generator isn't the tool, an unvented propane or kerosene space heater often is, and it comes with the identical twin dangers of fire and carbon monoxide poisoning, for the same underlying reason: burning fuel indoors without a chimney or vent to carry the byproducts outside.

Warning

Rules for using one anyway

Every kind of portable propane or kerosene heater sold for home use is classified as unvented. Health authorities don't recommend using them indoors at all; treat one as a genuine last resort, not routine heat.

If you do use one: run it only in a room with real ventilation (a cracked window or door), never in a small closed space, never while sleeping, and never in a bedroom. Use only the fuel specified for that heater (1K kerosene specifically, never gasoline or any substitute). Confirm it has an oxygen depletion sensor (standard on newer unvented heaters), which shuts the heater off automatically before oxygen depletion becomes dangerous, and pair it with the same battery-backed carbon monoxide detectors already covered above.

Kerosene heaters specifically cause an estimated 90 deaths and 2,300 house fires a year, most from flare-ups; keep anything flammable well clear of one and never refuel it while it's running or still hot.

Know how to shut off your utilities before you need to

This is a genuinely different skill from anything above: not preventing a fire or CO buildup you're causing, but responding to damage, most commonly from an earthquake, that's already happened. Find and test each of these now; a real emergency is the worst time to be locating a valve for the first time.

Where to find it: a gas shutoff wrench is inexpensive and sold at any hardware store; keep it attached near the valve itself with wire or tape so it's never missing when needed.

Tip

Glow-in-the-dark tape at the breaker panel and the flashlight's spot

A roll of cheap photoluminescent tape charges under normal room light and glows for roughly 20 minutes once the lights actually go out, long enough to find a flashlight in a nightstand or locate the breaker panel without fumbling in the dark. Worth knowing: most power outages are a tripped breaker, not a utility failure, so being able to find that panel fast in the dark solves more outages than it might seem.

Write your own plan, in one sentence

A shutoff valve you've never found before is a valve you won't find fast during an actual earthquake. Finish this sentence with your own real plan:

"Before , I will ."

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