How Long Can a Generac Generator Run Continuously?

Do you want to know the capabilities of your generator before you buy in? Read on to learn how long a Generac generator run can last.

A storm rages as thunder rumbles and rain pounds your windows. A chill runs up your spine as lights flicker and go out. Your life becomes a horror movie.

For what seems like eternity but it’s just an instant, your generator finally kicks on. Phew.

Once you remember your house isn't really haunted, you wonder, "How long can my Generac generator run?"

Ghosts aside, you need to know your generator’s run time. Between 2003 and 2012, there were 679 widespread power outages caused by severe weather. It’s likely you'll have any number of chances to see if your house shelters poltergeists.

So how long can your generator run? Keep reading to find out and to keep it running safely.

Generator Basics

Before you ever star in your own horror movie, you should know what kind of generator works best for your house, your Power needs and your wallet.

Power Priorities

Generators create power. So naturally, they're sold by power output, as measured in watts.

“Check the wattage to get an estimate of how many appliances the generator can run, the quality and consistency of the power it produces, and, of course, how long it'll run,” said Tobias Sommer, owner of Generators For Sale in Omaha.

For a home, unless your house has some crazy output, a 5500 watt generator should serve you well.

And if you want the best – a Generac generator?  Check out these options.

2 Available Flavors

Generators come in two flavors: portable and standby.

Remember the horror movie? When you pray for the lights to come back on? A standby generator with an automatic transfer switch will turn on automatically when the main power goes out.

You know, so you’re not that guy who goes outside in the dark to get stalked.

Standby generators are designed to power your whole house. Portable and inverter generators, on the other hand, are mobile.

“So they're used to run key appliances, rather than power everything,” Tobias said.

That doesn't mean they're the same. Portables are more for temporary use and construction sites. Inverters are quieter and work well for tailgating and camping.

Safety Tips

The first rule to help your generator run longer? Don't set your house on fire.

No, really. Generators don't do well when your house burning. They're funny that way. To stay in a healthy, committed relationship with your generator, follow these other key safety rules:

No Enclosed Spaces

Nobody should put Baby in a corner. Especially if Baby’s your generator.

Most generator-related deaths involve carbon monoxide poisoning from generators kept in enclosed spaces like basements and garages or inside the house.

“They can store up gases that really put your family at risk,” Tobias said.

How to avoid this? Keep your generator at a nice, healthy 15-foot minimum from your house and away from doors and windows. Sheds work great for storage but not running the unit.

And the easiest way to avoid the risk of CO poisoning? Keep a battery-operated carbon monoxide detector running at the same time. The new Generac portables will have a CO detector built in to help with safety.

Stock Up Beforehand

Funny story: Generators run on gas. When they run a long time, they run out of gas. When they run out of gas, they stop working.

Isn't it funny how that works?

So if you see a Wizard of Oz-type storm looming on the horizon, stock up on gas.

Standard safety warnings also apply to fuel. Store it only in an ANSI-approved container in a cool, well-ventilated area.

Avoid Electrical Hazards

A transfer switch assures your generator runs safely.

“It tells your house to run off the generator, not on utility electricity,” Tobias said. “That’s to prevent back-feed, a major safety hazard that can shock lineman working to restore your power.”

If you don't get a transfer switch, which is common for portable generators, you can have your generator run only certain appliances. Plug the appliances directly into the generator after you check cords for frays and cuts. Make sure the plug has all three prongs.

Note the word “appliances.” This does not include your furnace or well pump.

If it seems like a bad idea, it probably is. For other ways to help your generator run safely, check this list of safety tips.

How Long Can a Generac Generator Run?

One of three kinds of fuel makes your generator run: natural gas, liquid propane or diesel also regular gas.

Natural Gas

If your generator runs on natural gas, it's hooked to a supply provided by your utility company. It won't run out anytime soon unless a gas line goes down. Then you've got a problem. In this case, your generator won't have a fuel tank because it doesn't need one.

“Most standby generators operate that way,” Tobias said. “You'll know because standby generators need to be installed by pros.”

Propane or Diesel

If, however, your generator runs on propane or diesel, it will have a fuel tank. Usually, a diesel generator has a 24-hour tank, though there are 48-hour and 72-hour tanks available.

That said, because filled propane tanks only hold 80% of their rated capacities, a 500-gallon tank stores only 400 gallons.

If you have a propane or diesel generator, you probably have a fuel service provider. During extended outages, stay in touch with your provider to keep your tank topped off.

Regardless of whether your generator run time is indefinite or not, you'll still want to conserve usage. 

Oil for Lubricating and Cooling

Know what happens when an engine runs for a long time? Of course you do, it gets hot. Some like it hot, but generators don't.

For this reason, you'll need to periodically turn your generator off to cool it down.

Giving your generator a break doesn't just benefit your energy bill, either. During this pause, you can oil the generator's engine to help it run smoothly.

“Oil is your generator's lifeblood,” Tobias said. “It lubricates and cools the engine to keep it from seizing up or flaming out”.

As its engine runs, though, the oil breaks down, requiring you to replace it.

And no, do not put oil in the engine while it runs. Or when it’s hot. That's not multitasking, that's just a terrible idea.

Manufacturers recommend you change the oil every 200 hours of operation or once a year, whichever is more frequent. But if your generator deals with extreme outdoor temperatures or has to work harder, it will burn oil faster. During continuous operation shut down and check every 24 hours and keep topped off.

Be kind to your generator. Check the oil levels, but don't be over generous – too much oil is just as bad as too little. Like Goldilocks, it should be just right.

During a Power Outage

The moment of truth: When the lights flicker out and you wonder if your life just became a Stephen King novel.

First of all, don't panic. That only makes it worse. Really.

Get your bearings. If you have a standby generator on an automatic transfer switch, you should be fine. If you maintained your generator well beforehand, your lights will come on as soon as you hit the switch.

If it didn't, break out the flashlights, you've got work to do.

You should also make sure you've got enough fuel on hand, whether your generator is already running or not. Show your generator some love – give it a cool-down break every 24 hours until the power comes back.

Generac Generators (and More)

Of course, to have a healthy relationship with your generator, you need to own one and have it properly installed.

If you've already done your homework on Generac generators, you're in luck. Get started with a professional generator installation today.

Still got questions? Generators for Sale has answers. Contact us with whatever your question may be. We can't wait to hear from you.