How to Use a Home Generator

Updated October 23, 2026

Without a generator for your house, you're at the mercy of the weather and the local power grid to keep your lights on and your appliances powered. While many power outages are corrected quickly, others last hours or even days, depending on the severity of the damage.

This May Also Interest You: Everything You Need to Know About Home Generators

Installing and knowing how to use a generator for a house lets you keep at least the most essential electrical items running in your home.

What Are the Different Types of Home Generators?

The two main options are portable and standby generators. While they both provide a backup power source, the way they operate and how much work you have to do varies.

Standby Generators

An electrician permanently installs a standby generator for a home to connect to your home's electrical system. It automatically senses when the power shuts off and starts up quickly, often within seconds. Once that happens, it disconnects your home from the grid and takes over the power supply. The standby generator shuts off automatically after the electricity from the grid is back on and stable.

Safe generator placement is always important. Your standby generator will sit outside your home, usually on a concrete pad. It connects to a natural gas or propane line, so it has a constant source of power without requiring you to refill it.

Portable Generators

A portable unit is a movable generator that you set up when you need it. It doesn't turn on automatically, and it's not connected to a continuous power source, so refueling is necessary. You have to manually connect it to appliances in your home with an extension cord. Portable models typically have a lower power capacity than standby generators, which means you're limited in what you can power.

How Do You Determine What Size Generator You Need to Power Your House?

To determine the size of generator you need, it's important to identify your essential appliances and their electrical loads. Since the capacity is limited, particularly on portable generators, look at the critical items, like your refrigerator to prevent food spoilage and medical equipment to keep family members safe.

Then, calculate how much power those appliances need. Take into consideration running watts versus starting watts. Appliances with motors require more power when they start up, which is the starting wattage. Once they're going, the running watts are lower. Add the starting and running wattage to determine the total capacity each appliance needs. Combine the wattage of all the items you want to power to get the total capacity, and find the generator size that can handle that load.

Home Generator Setup: Hooking Up a Generator to Your House

Standby Generator Setups

Standby generators are permanently installed units that connect directly to your home's electrical panel and a fuel source, like natural gas or propane. They monitor your power supply and kick on automatically during outages. The system handles startup and shutdown when the power returns.

Portable Generators

Portable generators are more affordable units that require manual operation. You can run heavy-duty extension cords directly from the portable generator to your appliances, but this only powers a few essential items. The better approach is to have a transfer switch installed near your breaker box by a licensed electrician. When you need to run your generator during an outage, you plug a special cord into the generator outlet and the transfer switch inlet. This setup lets you power your home's circuits safely. The following information concerns portable generators.

How Do You Start a Portable Generator?

• Position the generator at least 20 feet from your home.

  This spacing prevents carbon monoxide from entering your home while the power source runs. Choose a flat, dry surface.

• Fill the oil and fuel.

  You may need to add oil to the generator if the levels are low. Then, fill the fuel tank while it's cool. Portable generators operate with different fuel types, so make sure you use the correct one.

Using a Portable Generator: Connecting Your Appliances and Electronics

• Turn on the generator without anything plugged into it. This process can vary by model. Typically, you need to turn on the fuel valve and open the choke to the full position. Then, flip the switch, push the button or turn the key to start the generator. After it runs for a few minutes, slowly adjust the choke to the Run position.

• Connect outdoor extension cords to the home backup generator. Run the cords into your home.

• Plug in the essential items you want to power. Be careful not to overload the generator.

• Refuel the tank as needed. Never add fuel while the generator is running. Unplug everything from the unit, shut it off and let it cool. Check the oil first, topping it off if needed. Then, add more fuel. Repeat the startup process and reconnect your items.

Portable generators power any corded appliance or device that plugs into an outlet, as long as you don't exceed the generator's capacity. If you want to use your portable generator for hardwired house appliances, you'll need an electrician to install a transfer switch. The device allows the generator to power items, like your furnace and AC, that are connected directly to the electrical system.

More Related Articles:

• How to Perform a Generator Load Bank Test

• Home Backup Generator Maintenance Checklist

• Feeling in the Dark? Here’s What to Do During a Power Outage

• How Much Does a Whole-House Generator Cost?

• How Much Do Electrical Repairs Cost? A Comprehensive Guide

How Do You Fuel a Generator?

Home generators run on various fuel types. Gasoline is common for portable models. Propane, diesel and natural gas are some other options. Standby generators typically connect directly to your home's natural gas line or a large propane tank so you never need to add fuel manually. The system draws fuel automatically as needed.

Portable generators require fuel refills periodically. This is where safety becomes critical. Never fuel a running generator. Always shut off the engine and wait for it to cool completely before opening the fuel cap. A hot engine can ignite fuel vapors, causing a fire or explosion.

Store fuel safely away from your home and any heat sources. Keep it in approved containers designed for fuel storage. Never store fuel inside your house, garage or near the generator itself while it's running. The heat generated by the engine can cause nearby fuel containers to ignite.

Generator Safety Tips

Generator safety is extremely important. These machines are helpful during power outages, but they also present serious hazards. Proper safety steps protect you, your family and even the utility workers trying to restore power. Here are some key safety rules:

• Operate your generator outdoors. Carbon monoxide poisoning from the exhaust can cause death. These invisible fumes come from all fuel-burning engines. An enclosed space can let carbon monoxide build to lethal levels. Additionally, keep the generator at least 20 feet from doors, windows and vents.

• Install a carbon monoxide detector. Even with your generator positioned properly, carbon monoxide can get inside. Use battery-powered detectors on every level of your home, and test them regularly.

• Protect your generator from weather. Can you run a generator in the rain? Not directly, as water and electricity don't mix. During wet weather, build or buy a canopy that keeps rain off while allowing ventilation. Never touch it with wet hands.

• Never back-feed power. Back-feeding happens when someone tries to plug a generator into the house by connecting it directly to an outlet. It’s extremely dangerous and can electrocute you, start fires and send power back through lines, endangering utility workers. Always use a properly installed transfer switch to connect your generator safely.

• Use proper extension cords. If you're using cords to connect your generator, choose heavy-duty, outdoor-rated types. Lightweight cords can overheat and cause fires. Keep total cord length under 100 feet.

• Watch your power load. Overloading can damage the unit or your appliances. Know your generator's maximum wattage capacity and total the wattage of everything you plan to run. Keep in mind that some appliances need extra power at startup.

• Read your owner's manual. Every model has specific operating needs and safety features. Review your manual before emergencies. Know where the shut-off switch is and how to stop the generator quickly if needed.

Operating a home generator safely requires attention to detail and respect for potential risks. Take these precautions seriously every time you run a generator. When used properly, your generator should provide reliable backup power without putting anyone at risk.

Can You Leave a Generator Running Unattended?

It is generally considered safe to let a generator run unattended. Just make sure you follow all safety guidelines before leaving your generator alone.