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Your Complete Generator Installation Guide

Get informed, plan your install, save time. Your guide to a safer home.

Consider This Before Installing Your Generator

There are many different generators to choose from that create convenience, increase your family’s safety, and can even add to your home’s value. However, generator installation is a process. It’s not as simple as going to the store, picking one up, and plugging it in. Planning takes time, and an understanding of the installation process will help you have the best overall experience.

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Why Install a Standby Generator?

If you’ve ever experienced a power outage that lasts more than a few minutes, you know how important having a backup power source can be. Within seconds of power failure, your standby generator will kick on, powering your entire home or just the essentials, depending on which system you have installed.


Permanent standby generators are installed by licensed electricians who prewire all the connections, ensuring that your unit and home are safe. The best part is, you don’t even need to brave the weather outside to flip a switch. The generator will sense when power is out and turn on automatically.


We often take electricity for granted, but in just a few hours without power, you can lose all the food in your refrigerator, temperature control is gone, and you won’t have Wi-Fi access. With a backup generator, your family doesn’t have to miss a beat.


A natural gas-powered generator can power your home for days or even weeks because it is directly attached to the fuel source. And with proper maintenance, a generator can last over 40 years.

Return on Investment

When you upgrade your home with a standby generator, you can see a return on investment in home value. According to Remodeling Magazine’s cost vs. value analysis, you can yield more than 50% of the generator project cost when you sell your home.

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Estimating the Cost of a Generator

A quick internet search will tell you the base prices of standby generators. However, it’s important to remember that price doesn’t include the installation, electrical and fuel source hookup, fuel cost, and maintenance costs. The following factors will affect the final cost of owning a standby generator.


How Much You’re Powering

The more you want to power around your home, the bigger generator you need, and the more it will cost for simply the machine itself.

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Fuel Source

Depending on the fuel you choose and how much you are using to power things around your house, you could pay around $40 per day for natural gas or upwards of $150 a day for propane.

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Installation Services

Your generator install team will include a small crew to pour concrete and move the generator into place, an electrician to connect the generator and install a transfer switch, and a certified gas professional to install the fuel line. This is absolutely not a DIY job, and quotes from contractors can range from a few thousand dollars to $9,500 based on how complicated the install is.

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You can expect to pay between $200 to $300 annually for the recommended regular maintenance with a service company.

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How Do I Find the Right Generator Installation Contractor?

Make sure you do your research ahead of time, finding a company with a long track record of positive customer experiences.

The main goal in installing a generator for your home is to have the peace of mind that you and your family will be safe in an emergency if the power goes out. But the wrong contractor can create a headache, drawn-out timeline, and even unsafe conditions.

Brothers’ teams of master tradespeople have been working to improve Maryland homes for over 35 years. When you choose to work with our electrical team for your generator installation you are choosing an experienced team of experts who will handle the process for you and provide a comprehensive warranty.

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Choosing the Best Sized Unit

What you need to power and the type of fuel source that powers your HVAC and appliances – electric or gas – will be the two significant factors in determining the size of the generator that you need. Most homeowners have similar needs during a power outage, but you will still need to choose between a few common generator sizes.

Before you meet with a contractor, make a list of the things you want your generator to power during an outage. Consider the list and notes on common needs and wants below.

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If you are on a well system, the well pump will need to be powered.

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Hot Water

Electric water heaters draw significantly more power than gas units.

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Heat and Air Conditioning

This is the single largest load in most houses and the biggest determining factor in the unit’s size. You may be able to decrease the unit size if you choose to power only the heat and not the air conditioning.

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Internet, Cable, and Wi-Fi

Depending on your lifestyle, for example, if you work from home, this could be a need vs. a want.

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A Functioning Bathroom

Many homeowners assume this room will be in the plan but make sure you mention it to your contractor.

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Major Appliances

Appliances such as the washer, dryer, dishwasher, oven, and electric range are things most people can’t do without for days at a time, but not connecting them to the generator can reduce the size of your unit.

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Additional Rooms

Infrequently used rooms such as the dining room, formal living room, and guest bedrooms can be left off of the generator to allot power for things you use more often.

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A few luxuries that homeowners choose to add to their generator include the garage door opener, entertainment center, and exterior lighting, but of course, you will need to size the unit properly to power these amenities.

Load Management

The latest transfer switches can turn off equipment or appliances if the load on the generator is too great. This load management allows you to choose a smaller sized generator while still powering what you want. However, the load management is usually connected to the generator, so you do not have direct control over what switches on or off, but each item is prioritized.

For example, if you take a shower during a power outage when the air conditioning is running, the well pump that supplies water combined with the air conditioning could overload the unit. Your generator will be programmed to know that the well is more important than the air conditioning. So, sensing the potential overload, it will automatically shut off the air conditioning until you’re done showering.

Common Whole-Home Generator Sizes

There are two main sizes of whole-home standby generators that most homeowners choose between, 12kw (60 amps) and 20kw (100 amps).

The smaller 12kw generator is capable of backing up the full list of needs and wants above IF the house has mainly gas appliances. It can also be connected to air conditioning using load management. The average installation cost for this smaller whole-home generator is between $9,000 and $12,000 depending on the amount of work needed for your specific home.

The larger 20kw generator is capable of backing up the list above, running 100amp service for electrical appliances and HVAC using load management. Plus, if the major appliances are gas, it can run a full 200amp service. This larger whole-home generator covers all the bases but does come with a higher average cost, often between $14,000 and $16,000.

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Generator Fuel Source Options

There are two fuel sources that can power your standby generator, propane, and natural gas. Each has its advantages and disadvantages, and whether your house is already hooked up to natural gas will be a big determiner of which one will work for your setup.



If you already have propane tanks, your contractor can easily connect the fuel lines to the existing tanks. Still, if you have no fuel source, propane gas is the best option as you can have bottles delivered or an underground tank installed more easily than getting new natural gas lines. However, you need to keep the gas tanks close to full by having regular refills. If the fuel tanks are low when a power outage begins, you may only have a limited supply. If an outage happens, you should order a refill immediately in case the outage lasts for days.

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Natural Gas

In Maryland, many homes are already supplied with natural gas through their local energy company. Your contractor can run gas piping and make connections to existing natural gas service. However, some areas are supplied with low-pressure gas for safety reasons, which is sometimes not adequate for a generator. In many cases, this can be resolved by upgrading the gas meter. But the upgrade must be done by the gas supply company and homeowner. In some cases, the gas company’s piping is not large enough to supply a generator, and the upgrade will cost far more than the project is worth.

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Finding the Best Location for Your Standby Generator

Proper Clearance

There are always clearances required, but they can vary based on the model of the unit as well as your jurisdiction. Most generators that Brothers installs must be a minimum of 18 inches from the house or any detached structure like a garage, shed, or fence. They also must be five feet away from any window, door, or opening to the home.

Distance from the House

Modern generators are relatively quiet, so the only reason to place them away from the home is for aesthetic purposes. But this requires the contractor to dig and install underground conduit for the fuel and electrical lines, then landscape to cover it back up, which adds substantially to the cost.

Level Surface

No matter where the generator is installed, it needs to be on a flat, level surface. Brothers always installs concrete pads for the generators to sit on to ensure that the generator’s foundation is both flat and stable. Generators placed on bare ground will eventually tilt due to the weight and vibration of the unit, which can damage them and even create an unsafe situation.

Out of Sight

In most cases, a good place for the generator is next to an air conditioning unit as that is usually the side of the house with the least windows and is rarely trafficked. However, it is still necessary to maintain proper clearances.

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Steps to Install a Standby Generator

Standby generators are powerful machines, and it takes more than merely placing it next to the house and connecting it to your home’s electrical system to install one. Learn what to expect before, during, and after generator installation.

1. Planning and Preparation for Generator Installation

Once you partner with a trusted contractor for your generator installation, you can start the planning process together.

Choose the generator size

Your contractor should help you choose the right sized generator based on how many things around the house you need to power.

Find the best location

While regulations vary by jurisdiction, there are usually only a few good spots for the generator to sit.

Secure permits

Ask your contractor if they will be working with your county or state to secure the right permits. Permits are absolutely necessary for these kinds of projects and a good contractor will handle this for you.

Pour the concrete pad

Generators must sit on a leveled gravel or concrete surface, which should be set up before installation.

2. Installing the Standby Generator

Most installations can be done in just a few days. On the first day, your contractor will likely bring a small team to help place the heavy generator as well as an electrician and plumber.

Secure the generator to the concrete pad

The generator can move and shift the ground due to vibrations when it is on, so it should be secured to your level concrete pad.

Connect the fuel line

A plumber will install the tubing connecting your generator to the fuel source, whether it be propane or natural gas.

Install the transfer switch

Transfer switches sense when the power goes out to switch the power source to the generator automatically. They come in different sizes and specifications and can be installed ahead of an electrical panel or after the main panel, controlling a small sub-panel.

Connect the electric

After installing the transfer switch, the electrician will connect the generator to your home’s electrical system.

3. Maintenance after Generator Installation

After installation, there are still a few things to remember to ensure that your generator continues to run safely and efficiently.


A local inspector from your jurisdiction will likely need to approve your installed generator to ensure that it meets all required safety standards.

Annual maintenance

The job for the professionals is not over after the install. You should have a contract with a service company to perform maintenance checks annually.

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Understanding Generator Maintenance Needs

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Transfer Switches

Transfer switches are programmed to run an exercise cycle once a week. This will start the generator (without affecting the house) and allow it to run for about 15 minutes. Like a car – it is important that the generator run to keep the hoses lubricated and the fluids from settling.

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Remote App-Based Monitoring

The Kohler generators that Brothers installs can be equipped with the Kohler OnCue system. The app allows homeowners to see the status of their generator on their mobile phone to confirm that it is running smoothly. The system also sends alerts if there is an issue and automatically notifies the service provider of any problems.

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Professional Service and Maintenance

All standby generators will require routine maintenance and should be serviced at least once a year by a professional. Usually, this is not included in the pricing or contract for installation from your contractor. However, your contractor should partner with local service companies and coordinate this for you.

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Generator Information from Experts in the Business

Not sure what’s next for your generator installation project? Dive deeper into the topics above with expert advice from Brothers.
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Home Generator Advice from Experts in the Business

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