Before the temperatures start dropping and the snow starts falling, you’ll want to take all possible measures to ensure your generator is up to snuff for winter use. Don’t let a last-minute snowstorm ruin your equipment. Take the time to learn all the ways an owner can be proactive in their generator maintenance so you’ll be ready for any weather.   

Why is Winterizing Your Generator a Necessary Part of Generator Maintenance?

If a generator is left alone throughout the coldest months, snow and ice have the potential to irreversibly damage it. Whether it’s cold temperatures making normal engine oil sluggish, dead generator batteries minimizing starting ability, or bad fuel gumming up the carburetor, winter can ruin your equipment.

To avoid your generator having to work overtime during a snowstorm, it’s important to invest time and effort into proper generator maintenance. Without it, there’s a chance the system will stall or refuse to start altogether, leaving you and your family in the cold and dark during times of distress. Luckily, there are countless tried-and-true generator maintenance methods for making sure a unit lasts throughout the year.

When Should You Prepare Your Generac Generator for Winter? 

The last thing you’d want is to start your wintertime Generac care too late. Though the exact timeline will depend on the unique weather conditions in your area, we recommend preparing your Generac for winter in either late October or early November. Inspecting and testing the unit before the truly cold weather starts setting in will give you plenty of time to change OEM parts, test the battery, and look at oil and fuel levels before it’s too late. 

Pro tip: If you get an alert that a major snowstorm is heading your way, then you’ll want to invest time in last-minute generator maintenance as soon as possible. Clear all the surrounding areas and test run the system so you know whether or not your home will be okay if the power happens to go out on your block. That way, if there is anything wrong with the equipment, you’ll be able to carry out the necessary generator maintenance and get your loved ones to safety elsewhere. 

What Do You Need for Generator Maintenance in the Winter? 

When it comes to setting up a generator for winter success, you don’t need to be a professional operator as long as you have the correct equipment on hand. Before the freezing temperatures hit, make sure your garage or shed has these vital supplies on hand for winter generator maintenance. 

Supplies to Stock for Winter Generator Maintenance: 

• Replacement parts: Having OEM replacement parts on deck will make it easier to upgrade your unit before a storm. Grab spark plugs, air and oil filters, and the type of small hardware your model requires to make sure you have spares at the ready.
• Fuel stabilizer: A chemical additive, fuel stabilizer is crafted to keep gasoline fresh and prevent fuel from blocking the carburetor when the engine isn’t running. Without it, the engine will likely sputter when prompted to turn on.
• Cold-weather engine oil: In winter, Generac generators require a more specialized, thinner oil, rather than standard oil, that is made to flow more easily in colder months. The diagnostic manual that came with your model should detail exactly what viscosity is recommended for low temperatures.
• Fresh backup fuel: Even if you’ve checked your current fuel levels and found they’re within the expected range, it’s a good idea to have newly filled backup canisters nearby. That way, you’ll be able to power on all your vital appliances for even longer, should the extreme weather conditions continue.
• Replacement batteries: Freezing temperatures can decrease battery capacity at a rapid pace. Grabbing an extra starting battery will give you peace of mind for using your Generac all winter long.

What Comes in a Cold Weather Kit for Generac Care?

While the exact components of a cold weather kit for generators depends largely on the model, the goal of wintertime generator maintenance remains the same: to help make sure the engine can reliably start once temperatures fall below 32 degrees. A typical air-cooled generator kit will include a battery warmer pad, a crankcase heater, and wiring harnesses and ties. Winter Generac kits for larger liquid-cooled or diesel units come with an engine block heater, oil blanket, battery warmer, and synthetic oil.

What Do You Need to Do to Prepare a Generator for Winter?

Between severe snowstorms striking out of nowhere and power outages caused by gusty winds, there are plenty of unpredictable conditions that could force you to switch from your normal utility grid to a standby generator. But don’t fret. As long as you complete this generator maintenance checklist before the first signs of flurries begin, you should be able to trust your generator to power on in the face of any winter disruption. 

Checklist for Generac Winter Preparation:

• Change the oil
• Test the battery
• Inspect the fuel
• Clear space
• Ensure airflow
• Examine air filters
• Assess ignition components
• Look at electronics

Change the Oil Out for Generac Winter Oil

The cold thickens normal generator oil, forcing the engine to work harder than necessary to provide power. To avoid this stress on your system, invest in a thinner oil specially designed for Generac winter use. When shopping, keep in mind which viscosity your model works best with and remember that a lower winter rating means the oil will pump faster during a cold start, reducing unnecessary wear on the equipment. 

Test the Generator’s Main Battery 

If the battery in your generator is old or worn down, it’s less likely to start in the cold. Examine the terminals for signs of corrosion and test the current battery during your initial generator maintenance inspection. If it hasn’t been changed in the last few years or shows signs of being faulty, grab a replacement battery. 

Inspect Fuel Levels within the Generator

Old fuel is one of the major causes of system failure during winter use. When it sits too long, the fuel becomes unstable and thick. Draining the stale fuel and refilling it with fresh gasoline before a snowstorm occurs is the best way to care for a Generac model.

Clear Space Around the Generator

For optimal performance, the area around your Generac unit should be clear of environmental debris. Before you run the equipment to check off the rest of the generator maintenance steps, make sure all leaves, dirt, snow, and ice are removed. This prevents the engine from overheating and lowers the risk of fire during operation.

Ensure the Generator Has Proper Airflow

When the airflow to a generator’s exhaust system is restricted, the potential for performance issues increases. During your assessment of the unit, look for and clear all intake areas of the generator to prevent ice from building up and damaging the unit throughout the winter.

Examine Each Air Filter in the Generator 

Extra windy winter weather can send snow and ice into the airbox of a generator. Before such storms swirl through your town, make sure to install a breather heater and oil filter heater to mitigate air filter damage. If snow does get in the air filter, there are additional generator maintenance steps you can take: just remove the filter, clean it out, and allow it to dry fully indoors before placing it back in the system. 

Assess All Ignition Components Within the Generator 

Responsible for igniting the fuel inside a generator’s engine, spark plugs are a necessary internal component for winter Generac use. If you see any corrosion, cracks, soot, or worn-out electrodes on the unit’s existing spark plugs, replace them immediately.

Look at the Electrical Cords and Outlets on the Generator

Just because the rest of your unit is updated doesn’t mean your generator maintenance is over. Before you give the all-clear, make sure that all the power cords and outlets are safe for use.

Keep an eye out for worn-out insulation, bent plug prongs, exposed wires, and any melted areas near outlets. If you do need a replacement, make sure it's rated for outdoor use and winter weather. 

Troubleshooting Tips for Generac Care in the Winter:

• Tip #1: During use, avoid letting the oil levels drop into dangerous zones and change the fuel out every 50 hours of use (the frequency may depend on your model).
• Tip #2: Consider adding an automatic transfer switch (ATS) to your generator to help it notice a drop in power and take over without human intervention.
• Tip #3: Keep the Generac generator manual on hand to identify what error codes mean in a timely manner.   

FAQ About Generator Maintenance in the Winter:

Can You Run a Portable Generator in Extreme Cold Weather?

By now, you probably know that standby and commercial generators are made to handle extreme weather, but what about portable models? The short answer? Yes, portable generators can still function in low temperatures and winter storms—it just takes a bit of preparation and generator maintenance. 

Before you assume your portable generator is ready for winter camping trips and construction site gigs, you’ll want to follow the same generator maintenance and preparation checklist as a traditional unit. When connecting it to your appliances, make sure to shelter the unit from the snow using either a ventilated portable generator tent or an open canopy. Once it's cooled down and unplugged, you can bring it back inside for safe storage.

Can You Run a Generac Generator Indoors During the Winter? 

No. Even in winter, generators should never be operated indoors. It doesn’t matter whether it's run in a garage, a basement, or an enclosed porch—the invisible, odorless carbon monoxide gas can kill within minutes of use. That’s why they’re specially designed to be able to run in any kind of weather.

What’s the Best Generator Cover for Winter? 

To protect your Generac from winter weather conditions, even while it’s running, you’ll want to invest in a high-quality running cover or tent. Typically a marine-grade vinyl or heavy-duty fabric stretched across a stainless-steel frame, these generator covers protect electrical outlets and encourage a cooling airflow, all while blocking freezing precipitation and supporting inches of snowfall.

Pro tip: Don’t be fooled into thinking that tight-fitting storage covers are the same thing. While handy for safeguarding your unit when stored away, these canvas and polyester covers cannot be put on when equipment is turned on without resulting in a fire hazard.

How Do You Use a Fuel Stabilizer in Generator Maintenance? 

Fuel stabilizer is one of the best options for managing fuel levels for Generac winter use. During your annual equipment examination, add fresh fuel and a stabilizer of your choice, carefully reading the instructions to get the correct ratio. Then, run the engine for about 10 to 15 minutes so the newly treated mix can reach the carburetor and fuel lines.

How Do You De-Ice a Generac Generator in Winter?

If you put off your Generac care routine, you might end up with an icy generator. But don’t worry, it is possible to safely de-ice it during generator maintenance for future use.

Start by completely shutting down and unplugging the generator. Then, gently scrape the ice from any intakes and exhausts you have access to, to help introduce new airflow into the unit. 

See whether the air filter is damp or frozen solid, and dry it out or replace it if it shows signs of being wet. For more stubborn patches of ice, you can try pouring warm water or melting it with a hair dryer. Once the ice is gone and all vital components are dry, you can plug the system back in and start it up.

What Happens If You Run a Generator With Snow on It? 

Professionals aren’t playing around when they say to never run a generator with snow on it. If you do, the engine will likely overheat, causing irreparable damage and creating a high risk of electrical shocks and short circuits. If you did not get a specially made winter Generac cover in time and snow has built up on your machine, make sure to clear a perimeter of space around the unit, remove all the ice, and allow it to completely dry before powering it on. 

Don’t just stand there! It’s time to winterize your Generac generator—or at least start thinking about the process. Find all the OEM replacement parts and generator accessories you need at Generator Magic today.