Generator Maintenance: Make Sure It Starts When You Need It

TL;DR: A generator is only useful if it actually starts during an outage. Here's the upkeep that guarantees it will.

_Last reviewed: July 2026 · 2 min read_

A backup generator is worthless if it won't start the night the power goes out — and the reason it won't is almost always skipped maintenance or stale fuel. Four habits keep it ready, and one rule keeps you alive: never run it indoors.

A critical safety note: generators produce carbon monoxide, a colorless, odorless, deadly gas. Always run one outside, far from windows and doors — never in a garage, even with the door open.

Why run a generator monthly?

Run it for about 15 minutes once a month under a little load. Regular operation keeps the engine lubricated, the battery charged, and the fuel system from gumming up — and it confirms the unit actually works before you need it. A generator that sits for a year often won't start in an emergency.

How should I handle generator fuel?

Stale fuel is the number-one reason generators won't start. Use fresh fuel, and add a fuel stabilizer if it'll sit, or run the tank dry before storage. Gasoline degrades in a few months and clogs the carburetor. Store fuel safely in approved containers, away from living spaces and ignition sources.

Where is it safe to run a generator?

Outdoors only — never indoors or in the garage. Carbon monoxide from a generator can kill in minutes in an enclosed space. Place it well away from the house, with the exhaust pointed away from windows, doors, and vents. Keep a working CO detector in the house as a backup.

What should I check before each use?

Check the oil level before every use — running low on oil ruins the engine fast (many units won't start with low oil, but don't rely on that). Glance at the air filter and fuel too. A two-minute check before starting prevents the most common failures and protects your investment.

Track the monthly run

Logging the monthly test run and oil changes keeps the generator dependable. Okoniq Property Hub keeps it with your home maintenance records in one private place — handy alongside your sump pump and storm prep.

Frequently asked questions

How often should I change generator oil?

Per the manual — often after the first 25 hours, then every 50–100 hours of use or annually. Portable units used in long outages may need it mid-outage.

Portable or standby generator?

Portable units are cheaper and cover essentials but need manual setup and refueling. Standby generators start automatically and power the whole home but cost more and need professional installation.

Okoniq Property Hub helps homeowners and landlords keep maintenance, bills, and contractor info in one calm place. Get started free.

FAQ

How long can a generator sit without being used before it won't start?

Most generators will have trouble starting after sitting idle for 3 to 6 months, primarily due to fuel degradation and carburetor clogging. Running it monthly prevents this issue entirely.

What size generator do I need to power my home during an outage?

A typical home needs 5,000 to 7,500 watts for essentials like the refrigerator, some lights, and a sump pump, while whole-house coverage requires 15,000 to 20,000 watts depending on square footage and whether you have central air or electric heat.

Can I use a generator in the rain or snow?

Yes, but only if the generator itself stays dry — use a properly ventilated canopy or tent-style cover that keeps rain off the unit while maintaining airflow and keeping exhaust vents clear.

How far from my house should I place a running generator?

At least 20 feet from doors, windows, and vents, with the exhaust pointed away from the house to prevent carbon monoxide from entering living spaces.