Maintain Generators and Carbon Monoxide Safety in Winter

Short, steady care keeps a generator running through winter storms — and keeps your family safe from carbon monoxide. I’ve kept portable and standby generators running during Missouri cold snaps for years. This guide lays out exactly what to check, how to site and run a generator in cold weather, and the safety gear and signs to watch for so you don’t have to guess in the middle of a storm.

Pre‑season maintenance and cold‑weather prep

Do these checks before the first storm. A tired generator in January is usually a maintenance problem waiting to happen.

• Read the owner’s manual. It’s the fastest way to get model‑specific oil grades, run intervals and cold‑start notes.
• Change the oil and filter if it’s been 50–100 hours or a season (use the oil weight the manual specifies for cold starts; many modern engines run well on a synthetic for low temperatures).
• Replace the air filter and spark plug if dirty or worn. Clean the carburetor or drain it if your model has a float bowl — old fuel gums up carbs in two seasons.
• Check the battery (charged and terminals clean) on electric‑start units; top up coolant on liquid‑cooled models per the manual.
• Run the generator under load for 15–20 minutes and plug in a fridge or space heater to exercise the alternator and carburetor; listen for odd noises and check for leaks.
• Stock a small maintenance kit: fresh oil, spare spark plug, air filter, socket set, funnel, rags and a fuel‑stabilizer bottle.

Tip from real use: label service dates on the generator with a waterproof marker — you’ll thank yourself after a few rough winters.

How to set up and operate safely in cold weather

Cold weather adds a few practical steps: keep the unit dry, easy to access, and far enough from the house that exhaust won’t come back inside. Follow these exact items each time you set up.

• Placement: always outdoors in the open air. Federal guidance recommends at least 20 feet from windows, doors and vents — and not under covered porches or carports where rooflines can trap exhaust. (See CDC guidance on generator placement.)
• Surface: level, firm ground or a 2×6/plywood platform to lift it above snow and slush. Clear drifting snow regularly so the exhaust and air intake aren’t blocked.
• Orientation: point the exhaust away from the house and neighboring structures. Check wind direction before starting — aim exhaust downwind.
• Weather protection: use a purpose‑made generator shelter or a commercial “storm shield” that keeps rain/snow off while allowing full airflow; never enclose the unit tightly.
• Electrical hookup: use heavy‑duty outdoor extension cords rated for the load, or install a transfer switch professionally to tie into home circuits. Do not backfeed the grid through a dryer outlet — that’s dangerous for utility workers.
• Fuel: use fresh fuel treated with stabilizer if you store it, and keep approved cans outside or in a detached, ventilated storage area per local codes. Rotate stored fuel every 6–12 months.
• Regular running: during a multi‑day outage run the generator on the recommended load schedule; when not in use run it at least 15 minutes monthly under load to keep things happy.

Carbon monoxide — signs, detectors, and emergency actions

CO is odorless and sneaks up when exhaust finds a way indoors. Be proactive rather than reactive: install alarms, know the symptoms, and practice a quick response.

• Detectors: install battery‑powered or battery‑backup carbon monoxide alarms on every level of the house and outside sleeping areas. Test them monthly and keep spare batteries on hand.
• Watch for symptoms: common early signs include headache, dizziness, nausea, shortness of breath, confusion or flu‑like feelings. If several people feel off at the same time, treat CO as possible and act immediately.
• If you suspect CO exposure: get everyone outside into fresh air right away, call 911, and seek medical attention. Turn the generator off and move it further away only after everyone is safe.
• Recordkeeping: after any CO event document placement, weather conditions and photos — and have your generator inspected before reuse.

Practical note: I keep a compact, battery‑powered CO detector in my “storm kit” along with headlamps and a small first aid kit. It pays off — I once caught a slow leak from neighbor exhaust drifting in a crosswind at night.

Quick checklist and common do’s and don’ts

Use this short list as your pre‑start routine when a storm is coming.

1. Pre‑start: check oil, fuel level and battery; clear snow 3–5 ft around unit; confirm exhaust direction and 20+ ft clearance from openings.
2. Start: move outdoors, start on a cold‑rated oil if required, run for 15–20 minutes and attach loads gradually; verify voltage/stability with a meter if you have one.
3. Fueling: never refuel a hot generator; let it cool, refuel outdoors with approved cans, and keep fuel away from living areas.
4. Powering the house: use a transfer switch installed by a licensed electrician; when using cords, run only appliances directly and avoid overloading circuits.
5. After use: shut down per manual, allow cooling, and store cover and spare fuel properly.

Do: practice a short generator drill with your family so everyone knows where the generator, fuel, CO alarm and shutoffs live. Don’t: run a generator in a garage, on a porch, or near vents — even if you think the air is moving away.

For a broader winter plan that pairs generator strategy with food, water and heat checks, see my home prep guide and stockpile planning for storms: Home Winter Storm Preparedness Essentials and the step‑by‑step math for reserves in Stockpiling Food and Water for a Two‑Week Winter Emergency.

Short, simple habits — a monthly run, a small maintenance kit, correct placement and working CO alarms — keep you warm and keep the family safe. Do the checks now, and you’ll be able to think clearly and cook dinner when the next storm arrives.