What to do if?Reviewed: 2025-12-27~1 min

What to do if your generator won’t start during a power outage in freezing weather

Short answer

⚠️Depends / use caution

It depends on the fuel type, battery condition, oil viscosity, and how cold it is. Try safe cold-start steps like warming the battery, checking fuel type for cold performance, and reducing wind exposure—while avoiding risky heat sources or indoor use.

Why people ask this

In a power outage during freezing weather, a generator can be a lifeline for heat and essentials. But cold-soaked engines, thickened oil, and iced fuel components often prevent starting. People want quick, safe steps that work in sub-freezing temps without creating carbon monoxide or fire risks. They also need fuel-specific tips (gasoline, diesel, or propane) because cold affects each differently.

When it might be safe

Move the generator to a sheltered outdoor spot (out of the wind and snowdrift, but never indoors) and warm removable parts like the battery indoors, then reinstall.
Use a hair dryer or heat gun on low to gently warm the carburetor/throttle body and oil sump for a few minutes, keeping the heat source and extension cords away from fuel vapors and snow.
For gasoline units, ensure fresh winter-grade fuel; for diesel, add an anti-gel and use winterized diesel; for propane, use a full cylinder kept above about 20°F and keep the regulator dry with a cover.
Use the correct cold-weather oil (e.g., 5W-30 synthetic) and verify the choke/primer procedure for cold starts; after it fires, gradually reduce choke to avoid flooding.
Charge or jump the starter battery using a smart charger or vehicle (parked outdoors), and try a few shorter cranking attempts with rests to avoid draining it in the cold.

When it is not safe

Running the generator in a garage, porch, or near doors/windows; snow-blocked exhausts can force carbon monoxide back toward the home.
Applying open flame, torches, or combustion heaters to warm the engine, regulator, or fuel lines.
Backfeeding a home by plugging into a wall outlet or using makeshift cords without a transfer switch.
Overspraying starting fluid/ether, especially into a warm glow-plug diesel or through an air heater, which can damage the engine.
Defeating low-oil or other safeties, or operating with packed snow around the muffler or intake.

Possible risks

Carbon monoxide poisoning from operating too close to the home or with blocked exhaust in snow and wind.
Fire or burns from improper heating methods or extension cords overloaded in freezing, wet conditions.
Electrical shock or electrocution from wet outlets, ice-covered cords, or backfeeding utility lines.
Engine damage from thick oil, fuel gelling/icing, or heavy ether use in sub-zero starts.
Personal injury from repeated hard pulls on a recoil starter, frostbite, or slips on ice around the unit.

Safer alternatives

Use an indoor-rated, vented emergency heat source (properly certified) with a CO alarm, or relocate temporarily to a warming shelter.
Leverage a battery power station for critical loads and recharge it via a vehicle alternator outdoors with a proper inverter.
Run your vehicle as a charging/heat source only outdoors, using phone/laptop charging while ensuring tailpipe is clear of snow.
Conserve heat: close off rooms, add insulation around pipes, and let faucets drip to reduce freeze risk until conditions improve.
Check with neighbors or community centers for shared power, or a loaner generator already set up for cold starts.

Bottom line

In freezing weather, cold fuel, thick oil, and weak batteries often keep generators from starting. Focus on safe cold-start basics—fresh winter-friendly fuel, correct oil, gentle pre-warming, and proper choke/battery care—while keeping the unit outdoors and cords dry. If it still won’t start, switch to safe alternatives rather than taking risks with heat or indoor operation.