Winterizing a generator matters for two different scenarios: a generator being put into storage for the season, and a generator you expect to actually use outdoors in cold weather. The prep is different for each.
If you're storing it (not using it this winter)
- Add fuel stabilizer or run the tank dry before storage — gasoline left untreated for months is one of the most common reasons a generator won't start next season
- Change the oil before storage rather than after — old oil sitting all winter is harder on internal components than fresh oil
- Disconnect the battery (electric-start models) or use a maintainer to prevent it from draining dead over the season
- Store it somewhere dry and cover it — moisture is the main enemy of a generator sitting unused for months
If you'll actually run it in cold weather
- Use fresh, cold-weather-appropriate fuel — some fuel blends perform worse in freezing temperatures
- Check your owner's manual for a cold-start procedure — many generators have a choke or cold-start setting that makes a real difference below freezing
- Keep the generator itself as warm and dry as practical (a generator tent/enclosure rated for ventilation, not a fully sealed cover) — extreme cold makes starting harder and can affect oil viscosity
- Battery-powered electric start units lose some cranking power in the cold — a healthy, fully-charged battery matters more in winter than any other season
Don't skip snow and clearance checks
If you'll be running the generator outdoors during a winter storm, plan its placement in advance — 20+ feet from the house, clear of snow drifts that could block the exhaust or intake, and positioned so exhaust doesn't vent toward a door or window. See our carbon monoxide safety guide for the full placement rules, which don't relax for cold weather.
For the routine schedule beyond winter-specific prep, see our full generator maintenance checklist and our exercise schedule guide.