How to Prepare Your Home Generator for Winter Storms

You invested in a whole-home standby generator so that your family can maintain power during unexpected outages, but if you want true peace of mind about your system’s performance, you need to invest in routine maintenance.

A well-maintained generator is far more reliable when the snow is falling, temperatures are dropping, and the grid is under stress. Our guide covers everything you need to know to prepare your generator for the winter season so you can head into the colder months fully confident in your backup power source.

Step 1: Review Your Generator’s Maintenance Schedule

Every whole-home generator has a recommended maintenance schedule provided by the manufacturer. If you haven’t reviewed yours recently, now’s the time. Most systems require annual or semi-annual maintenance, and the start of winter is an ideal moment to make sure all recommended services have been completed.

Look through your maintenance log (or create one if needed) and verify:

When the last service was performed
Whether the oil and filters have been changed
If any prior issues were noted but not addressed
Whether your warranty requires specific maintenance intervals

If you’re unsure about any of these details, a professional inspection will help you get back on track.

Step 2: Check the Fuel Supply

Fuel problems are one of the most common reasons generators fail during winter storms. This is because cold weather thickens oil, impacts fuel flow, and increases the system’s workload. So, no matter if your standby generator runs on natural gas, propane, or diesel, make sure your fuel source is stable and ready.

For Natural Gas Generators: Confirm with your gas provider that service to your home is reliable and unaffected by seasonal changes. Although rare, extremely cold weather can sometimes reduce pressure in a gas system.
For Propane Generators: Check your tank level and top it off well before winter storms hit. Remember, propane deliveries may be delayed after heavy snowfall or during icy road conditions.
For Diesel Generators: Because diesel can gel in cold temperatures, ensure you have a winter-grade fuel blend or additives designed to prevent thickening.

Regardless of your generator’s fuel type, always keep the area around the fuel source accessible and clear of snow, ice, and debris.

Step 3: Check & Change the Oil

Cold temperatures make oil thicker, which can strain your generator’s engine. Before winter storms roll in, check the oil level and quality. If your generator is due (or close to being due) for an oil change, it’s best to complete it before harsh weather hits.

Fresh oil keeps internal components properly lubricated and reduces wear during long run times. Pair the oil change with a replacement of the oil, air, and fuel filters for optimal performance.

Step 4: Test the Battery & Electrical Connections

Just like your car battery struggles on a freezing cold morning, your generator’s battery finds it hard to operate well as temperatures plummet. This occurs because the chemical reactions inside the battery slow down, reducing its ability to provide the strong current needed to crank the engine. The good news is that there are steps you can take to protect your generator’s battery during the winter season.

Start by checking the battery terminals for any signs of corrosion (this typically includes a white or teal substance). This build-up can increase resistance and prevent the necessary power from reaching the starter. If you see corrosion, clean it off carefully with a wire brush and a mixture of baking soda and water.

Next, check the voltage. A healthy generator battery should read between 12.5 and 13 volts when the unit is at rest. If your battery is more than three years old, you should strongly consider replacing it before winter settles in. After all, it is far better to replace a battery a few months early than to discover it is dead in the middle of a blizzard.

Step 5: Run a System Test

Most whole-home generators include an automatic weekly or biweekly self-test feature, but that shouldn’t replace a manual run before winter. Perform a test run long enough for the generator to reach its normal operating temperature.

During the test, keep an eye (and ear) out for the following:

Unusual noises
Excessive smoke
Vibration or shaking
Odd smells
Irregular power output

If anything seems off, schedule a residential electrical service right away. Problems that appear minor during a test can become major issues during a real outage.

Step 6: Update Your Transfer Switch Settings

The automatic transfer switch is what tells your standby generator when to turn on and off during an outage. Before winter storms begin, verify that your switch is functioning properly.

Check that:

It responds immediately during a simulated outage.
There are no loose or corroded connections.
All wiring appears intact.
The switch casing is sealed from moisture.

If you haven’t had the transfer switch inspected recently, winter is an ideal time to schedule a professional check.

Step 7: Keep Spare Supplies on Hand

A well-prepared homeowner always keeps a few spare supplies available, especially during the winter when storms may prevent you from leaving your house. Consider storing:

Extra oil
Air and oil filters
Fuel additives (if applicable)
A backup battery
Snow-clearing tools to keep the generator accessible

Having these supplies nearby can save time and stress during extended outages.

Step 8: Protect the Generator From Snow & Ice

Your standby generator is air-cooled (or liquid-cooled with a radiator), meaning it needs a constant supply of fresh air to operate without overheating. It also needs to expel hot, potentially deadly fumes safely away from the unit and your home. Unfortunately, heavy winter storms can interfere with these processes. For example, drifting snow can bury the unit and block the intake vents. If the generator tries to run while buried, it can overheat and shut down in minutes, or worse, suck in snow that melts and damages internal electronics. Additionally, if the exhaust is blocked, the unit will shut down due to backpressure or potentially let dangerous carbon monoxide run back into your home.

To prevent any operational issues and safety hazards, make it a habit to clear a path to your generator every time you go out to shovel your driveway. Clear a five-foot perimeter around the unit, brush the top of the unit off, and ensure the louvers on the sides are completely unobstructed.

Most importantly, never run the generator if it is encased in snow or ice.

Count on Us to Get Your Home Generator Ready for Winter

Nothing provides peace of mind quite like a thorough generator inspection from a trained professional. Our technicians at A-1 Electric can evaluate your unit’s internal components, test its electrical connections, examine the fuel lines, verify safe operation under winter conditions, and recommend necessary services. Contact us today to schedule an inspection and head into the winter season with complete confidence.