How to Winterize Your Generator? [Easy Steps]

Last Updated: September 16, 2022
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As the temperatures start to drop and become colder, you’ll want to be sure that your generator is properly winterized, whether it is a portable model or a standby model.

Those of you who live in an area where it gets really cold during winter or have previously been hit with freezing temps know that there is nothing worse than having power cut off during the coldest time of year.

If it’s going to be very cold, it’s very critical that your generator be prepared to start in the cold weather and be able to run smoothly. There’s nothing worse than being stuck in freezing weather and not being able to use your generator or heat your home.

Here are some tips for winterizing your generator to help you stay warm in the winter.

Winterize Your Portable Generator

1. Portable Gas Generator Storage – If you not going to use it

  • Add an appropriate amount of gasoline conditioner and stabilizer to the fuel system.
  • Run unit to ensure that all mixed fuel is in the fuel system.
  • For SHORT TERM storage: Run the generator for 2 minutes, then turn off the engine. Close off the fuel control valve and run the unit until it shuts down.
  • For LONG TERM storage: Run the generator until all the fuel in the tank and carburetor is used up. When the generator starts to die, move the choke lever to the neutral position. Turn the ignition off during operation to shorten the run time of the generator.
  • Take out the spark plug, fill the cylinder with around 5-10cc of engine oil, slowly crank the handle 2 or 3 times, and then insert the spark plug.
  • Clean outside the generator and apply a rust preventive.
  • Store generator in a dry place that has good ventilation.

2. Running Portable Generator in the Winter

There are some precautions you should take before starting up your portable generator during the winter months. First, you should wait 10 minutes after starting the generator or engine before you start loading it.

Running the engine for 10 minutes helps warm the engine by allowing the fuel to circulate and move around. Use a fuel stabilizer, as mentioned above, to prevent your fuel from being ruined by the cold.

Before turning on your generator, check to see that everything is in proper operating order. This will help you avoid any breakdowns and provide the necessary amount of electricity.

Here are some tips on how to winterize a generator.

1. Do a Deep Clean and Check the Lines

It’s important to keep the area around your generator clean and free of obstructions like dirt, leaves, and branches. You should use a wet towel to clean your generator, but you should take care not to get the control panel wet. Use an air blower to get into the tight spaces.

The fuel and oil in your portable generators get dirty and gum up the lines and the carburetor as you use them. Cleaning, checking lines, and replacing worn or broken parts are all part of routine engine maintenance. There is no better time than now to get this done than over the winter months if you didn’t do it throughout the season.

If you keep your generator in good working order and do the recommended maintenance, it should last you all through the cold season.

If your generator isn’t working, you can either perform maintenance on it yourself or hire a technician. Test the unit after checking it, cleaning its parts, and refilling its fluids. To keep your generator running in the cold, you should use winter fuel additives and switch to winter-grade oil.

2. Check the Battery 

Batteries do not fare well in sub-freezing temperatures. Make sure the battery for your electric-start generator is charged and ready to go before you need to use it. It is advised that the battery voltage be checked on a regular basis. If your battery keeps dying, you should replace it before the winter weather sets in.

3. Invest in A Generator Shelter

It’s been shown that snow and ice can be harmful to your generator. If you want to prevent the pipes and components of your generator from rusting due to moisture, a generator shelter is your best bet. Make sure that ice and snow haven’t blocked the exhaust port and vents by inspecting them on a regular basis.

4. Check Exhaust & Vents

Keep in mind that the engine of your generator needs adequate ventilation in order to function properly. Due to ice dams and snow accumulation, exhaust ports and air vents frequently become blocked during the winter. These locations may be inaccessible if they are blanketed with snow, which then freezes and thaws again, forming a solid block. Inspecting for buildup and clearing it away on a regular basis will keep everything running smoothly.

5. Get a Block Heater

Having a heater for the engine block is a good idea if you live in a region where winter temperatures frequently drop below freezing. Water jacket heater is another name for this heater. Having a warm engine and oil is a big help when starting the vehicle from cold. It’s important to remember that not all generators can handle the heat produced by engine block heaters. To ensure a proper fit, always refer to the manufacturer’s instructions.

6. Get Some Extra Fuel

Always have a plan B and enough fuel on hand for extended use. In the midst of a blizzard and power outage, the last thing you need is to find yourself without fuel. In the event of a power loss, preparation is essential as it might linger for days.

7. Do a Test Run

Every three months, you should run your generator for at least 30 minutes to ensure it is in good working order. Inactivity for extended periods of time can reduce the effectiveness of your generator. Similar to keeping your car’s battery charged, frequently running power generators will help charge the battery and lessen the likelihood of the system failing to turn on.

Winterize Your Standby Generator

The sole purpose of a standby generator is to wait in readiness for use. A standby generator is a backup power source that may be turned on in the event of a power outage, major storm, or other disaster that causes you to lose electricity.

Any power outage is stressful, but adding the stress of a damaged standby backup generator due to improper winterization is a recipe for disaster. Take these measures to winterize your standby generator and be ready for any emergency.

Here are a few ways to winterize your standby generator.

1. Maintain the Area Close to The Generator

There are vents on the outside of the cabinet that allow air to circulate around your standby generator. Blocking these vents with snow, ice, leaves, or other debris inhibits the unit from ventilating properly. As a result, overheating and other problems may occur. Keep the unit and its immediate vicinity free of snow during the winter. A minimum of five feet of space is required surrounding the generator at all times.

2. Create a Path to The Generator

If you need quick access to your standby generator to fix any faults, you should clear a path to it in the snow. You or a nearby professional can easily service, maintain, or repair your generator in this way.

For the same reason, you should make sure that there is simple access from the generator to the outside inlet plug of your home.

3. Ensure that The Battery Is Charged

Batteries degrade in colder temperatures and don’t perform as well as they do when the weather is warmer. Make sure your standby generator’s battery is in good shape before the winter. The battery may not be able to hold a charge if it is nearly dead. If that’s the case, it could be time to get a new battery.

4. Workout Your Generator

Your standby generator is like your automobile in the winter; it needs to be started and run for a few minutes before you use it, especially if it has been sitting for a while during cold weather. Your generator may not automatically start up or function properly in temperatures below 40 degrees Fahrenheit if you don’t perform this test. By running the generator for 10 minutes once a week, you can keep the moving parts oiled and the seals in good shape.

5. Invest in A Cold-Weather Kit

A cold weather kit is a helpful tool for making your standby generator ready for the winter. The majority of generators have cold weather kits designed by the manufacturer to improve their performance in the winter. Get advice on the best cold weather kit for your generator from the experts in your area, and have them winterize your standby generator for you while they’re at it.

The standard components of a cold-weather survival kit are:

Battery warmers: As we’ve already said, batteries don’t last as long when it’s cold, and they can’t work as well as they could when it’s warmer. If the temperature outside drops below 40 degrees Fahrenheit, a regulated battery warmer will turn on automatically to keep your battery at a constant, comfortable temperature.

Crank case heater: In the summer, the oil in your generator acts like a good lubricant. In the winter, though, it might become a slushy substance that reduces friction. In extremely cold weather, a crank case heater keeps the oil from solidifying, keeping the generator running smoothly.

SAE 5W-30 oil: All most all generators use regular 10W-30 oil. When utilizing a heater, however, it is recommended that 5W-30 synthetic oil be used.

Frequently Asked Questions

Can a Generator Be Left out In the Cold and Snow?

No. Generators are not friends of water in any form. Once you’ve finished winterizing a generator, put it away in a dry place like a garage or shed. If you can’t store it indoors, put it on a pallet or other stable base, and cover it with a canopy. This blocks the path of any melting snow, preventing any potential flooding.

Do All Diesel Engine Generators Need to Be Winterized?

Since power outages are more common in the winter, commercial establishments must have generators to ensure uninterrupted operations. Your business diesel engine generator should be winterized so that it continues to function when needed.

Can You Run Down the Fundamentals of Winterizing a Diesel Generator?

There are several precautions you should take with your portable generator if you won’t be utilizing it throughout the winter months. However, these procedures will vary depending on whether the generator or engine is powered by diesel or gasoline.

When deciding where to keep a diesel engine or generator, the fuel itself is the most important factor. Due to the Paraffin, a type of wax used for lubrication, diesel fuel can gel at freezing temperatures. Because of this wax, diesel fuel starts to solidify like a gel when the temperature drops.

Avoiding gelling in diesel fuel may be as simple as adding cold flow improvers, but doing so in excess will reduce the fuel’s effectiveness. You can also try switching to a diesel fuel that is optimized for usage in cold weather to avoid the problem of gelling fuel. These fuels are less likely to gel when exposed to low temperatures.

When preparing a diesel generator or engine for the winter, the next step is to drain the water separator and replace the filters. Any amount of water in the engine can cause difficulties, but water that goes in and then freezes because of the cold can cause significantly more damage. This can be avoided by draining the water separator and replacing the water-absorbing filters prior to storing the engine.

A standby generator that uses diesel fuel can experience the same difficulties as a portable generator while operating in extremely cold temperatures. Diesel fuel is susceptible to the same kind of gelling and requires a CFI or a mechanism to heat the supply lines to the engine. The latter action prevents the fuel from entering the engine from freezing and gelling in the generator by warming it up.

To do so, you can invest in gasoline lines or diesel fuel storage tank heaters. If you want to avoid buying anything that doesn’t work on your generator, or using something that doesn’t work and damages the engine while nullifying your manufacturer warranty, consult the operator’s manual before making any decisions on winterizing your generator or engine.

What Precautions Should Be Taken when Winterizing a Generator?

Power generators must be used in a safe manner. The generators must have enough ventilation. Second, generators could produce harmful levels of carbon monoxide, so a carbon monoxide detector should be installed. Finally, avoid placing the generator in damp places, as this might result in potentially fatal electrical shocks.


When winterizing a generator, whether portable or stationary, it is important to follow the manufacturer’s instructions carefully and avoid doing anything that could damage the unit.

Properly winterizing your generator may save you time and money, both of which are quite valuable, and understanding what to avoid when it comes to cold weather could mean the difference between a long-lasting, dependable generator and one that fails after only one winter.

Never underestimate the harm that cold weather can do, and be ready to have your generator professionally winterized so that you can add some years to the engine’s life.

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Thornton M. School

I am a mechanical engineer with years of experience working on Internal combustion engine and fixing electrical and mechanical systems, generators, transfer switches, and equipment related to storm water and sewage pumping stations.