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Can You Fill a Generator While It’s Running?

Can You Fill a Generator While It’s Running?

Generators spare you from the consequences of sudden power outages as the world now experiments with hybrid work setups. When it starts to run out of fuel, though, you may wonder if you can refill it while it’s still running.

You should not fill a generator while it’s running for safety reasons. Doing so exposes you to severe hazards, which include fire and explosion. Instead, turn the generator off and patiently wait for the equipment to cool down before adding fuel.

Generators have the power (pun intended) to be extremely useful, but they can also do serious harm. The following sections elaborate on how to run your generators safely.

Why Shouldn’t I Refill My Generator While It’s Running?

You should never refill your generator while it’s still running because doing so could pose great danger. Refilling the generator before it’s been turned off and fully cooled might save you some time, but a wrong move could lead to a fire outbreak as the fuel used is highly combustible. 

Depending on your generator, it most likely runs on diesel, natural gas, or gasoline, among others. However, no matter which fuel you use, they are the kind to catch fire easily. 

If your generator uses diesel, you may argue that your fuel is generally safer than gasoline, and in part, you could be right. Diesel is indeed less likely to catch fire than gasoline, but its flammability is still really high.

If you’re worried about downtime, familiarize yourself instead with how long your generator can run at total capacity. That way, you’ll be able to predict when you need to refill your generator and schedule the refill during work breaks or when you least need to use it.

Another option would be to opt for a generator whose capacity can last an entire workday or is most suited to your needs. However, refilling your machine while it’s running is always off the table.

Are Generators Generally Safe To Use?

When used correctly, generators are safe to use. What’s important is for you to take note of the necessary operating precautions before running them. As long as these are followed, there’s no need to worry.

As most people will likely only use generators during emergencies, it may be easy to forget safety precautions when using the machine. Hence, it is essential to orient your entire family on how to use generators in general. 

Familiarizing yourself with the correct operating procedures and highlighting major “don’ts” will minimize hazards and improve your family’s safety. 

How Do I Run My Generator Safely?

To run your generator safely, turn it off when refueling and keep it in a well-ventilated area. These are standard best practices. Additionally, each generator comes with its own manual, and checking the document before running your machine is essential.

Let us delve deeper into the ways to ensure your safety when using your generator. 

Turn Off the Generator Before Refueling

If anything, this article emphasizes how refilling fuel into your generator should only be done when the machine is turned off and fully cooled down.

Combustible materials such as the fuel you use to run your generator easily catch fire at elevated temperatures. You’ll notice your generator is hotter than room temperature when it’s running, which is why you need to turn it off first whenever you need to refill it.

Do Not Refill Fuel When the Generator Is Still Hot

Additionally, shutting the generator down isn’t enough. As we’ve previously explained, combustion takes place at elevated temperatures, so the goal is to bring down the temperature before refilling your generator. An hour of no power is better than exposing yourself and others to the possibility of an accident. 

Ensure Adequate Ventilation

Another important consideration is ventilation. Incomplete combustion of fuels such as the ones that power your generator releases carbon monoxide (CO) into the air. Carbon monoxide is highly toxic and can be fatal even with just a few minutes of exposure.

Hence, ensure your generator is set up in a well-ventilated location to avoid CO poisoning.

Do Not Expose Generators to Water

Running the generator in a dry area is another important precaution. When water comes in contact with a generator, its conductive nature makes it quickly catch electricity, potentially leading to electrocution (source).

This makes it clear that operating your machine on a rainy day is a major no-no if you don’t have any means to protect it from water droplets. In severe storms, it may be challenging to ensure that generators are placed in a well-ventilated and water-free location. Unfortunately, this means it’s also unsafe to use your generator at the time.

Read Your Machine’s Instruction Manual 

Some generators may have precautions specific to the equipment. Hence, it’s important to browse through the manual before operating your machine.

Another compelling reason to check your manual and familiarize yourselves with general safety tips is that different machines can have varied installation procedures. Setting up your generator incorrectly can expose you to severe hazards, so the process of ensuring your safety must begin during installation.

Have a Fire Extinguisher Ready

While generators are generally safe, the possibility of catching fire is among the most common issues you’ll need to prepare for to be on the safe side.

To be clear, following your generator’s safety operating procedures and the other tips mentioned above will make it less likely to cause a fire.

However, in an emergency, having a fire extinguisher can spare you from a lot of trouble. Place your fire extinguisher where it’s easy to grab and operate in case of fire – close to the generator but still at a safe distance. 


Generators allow us to keep working even during power outages. Still, keep in mind that this added flexibility comes with risks and requires some level of precaution. There’s no need to worry so much, though, as running a generator is generally safe as long as you follow its operating procedures correctly. 

The most important thing to remember is never to refill your generator while it’s running or when it’s still hot. It may be tempting to save a few minutes by not having to restart the machine, but it’s not safe at all and may cost you more afterward.

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