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Verified Reviews for Generator Install pros in Marion, IL

*The Angi rating for Generator Install companies in Marion, IL is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Install needs.

*The HomeAdvisor rating for Generator Install companies in Marion, IL is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Install needs.

Last update on February 24, 2026

Find Generator install pros in Marion

Avatar for Holtzclaw Electric
Holtzclaw Electric
4.9(
9
)

Serving Marion, IL and surrounding areas

Approved

In business since 2009

Credit card accepted

Offers commercial services

"Call this electrician! He s worth your call, don t wait for him to call you! He was fair, honest and went above and beyond our expectations. We got two other quotes, one being from another company (Service detectives) who charged us $89 for a QUOTE and then quoted us $19k for everything we wanted done. For the things we needed done (not the whole house but a new meter outside, wiring to the inside, new panel and several outlets rewired) Holtzclaw Electric did for 3 times less than S.D. Just call Brandon. You won t regret it."
Response time2 hrs
Recommended by100%of homeowners
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Avatar for Electrical Detectives
Electrical Detectives
4.1(
9
)

Serving Marion, IL and surrounding areas

In business since 1968

Warranties offered

Credit card accepted

"As a professional in a similar field, these folks know how to get the job done. Can't say you can hire a company that has the T's crossed and their "i's" dotted more so than these guys. Happy to work with them in the near future!"
New breaker box
New meter service 2012
New breaker box with surge protection
Kitchen lighting
Kitchen lighting

+1

Response time1 day
Recommended by85%of homeowners
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Avatar for Hope Electric
Hope Electric
4.8(
9
)

Serving Marion, IL and surrounding areas

In business since 2019

Free estimates

Offers commercial services

"John installed an outdoor generator connection and a lockout on the main panel. A very fair price, good communication and a very professional, quality installation."
Response time1 day
Response rate99%
Recommended by100%of homeowners
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Fitzgerald Electrical Services -
New to Angi

Serving Marion, IL and surrounding areas

In business since 2009

Free estimates

Emergency services offered

Fitzgerald Electrical Services is an obvious choice for all your electrical needs. We have the power to perform and can handle any job from computer networking to electrical wiring and panel upgrades for a remodel or addition. We are experts in the installation of in-ground pools and can also assist with repair work associated with your swimming pool and the accessories and equipment. Free Estimates within 30 min drive We proudly obtain a Cape Gerardo License #852, expires March/2014. Outdoor lighting, home theater systems, telephone jacks, surveillance systems, etc..."If There is Wire to It...We Do It".

Kohler Emergency Generators and Transfer Switches
Undergound Electrical Conduits/ Electrical Room
High Voltage Transformer
Landscape Lighting Design and Installation
Data Center Lighting

+15

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Sides Contracting, LLC
New to Angi

Serving Marion, IL and surrounding areas

Hello, I’m Dan, and myself and my crew are most capable of taking care of nearly every project you may have. With our combined experience in many fields, you’ll get superior service, quality workmanship, and fair, competitive pricing. We work when others won’t, providing standard rates on nights and weekends. \n From home appliance repair and installs, to whole home renovations, HVAC, plumbing and electrical, decks, siding and so much more, not only can we do it, we can do it beyond your expectations. For the rare instances we encounter that we aren’t 100% certain we can exceed your expectations, we can refer someone who we know will satisfy you. \n Free estimates, advice, and all work warrantied. \n Local, same day service most days, 24hr max arrival windows for repairs. \n Give us a chance to impress you, and you’ll be the person who can always tell your friends and family “I know a guy!”

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Generator Install questions, answered by experts

The cost to install a whole-house generator averages $5,200, with a typical price range of $1,500 to $8,900. However, total costs can vary from $400 for a small portable unit to over $18,000 for a large-capacity system. The most significant cost factor is the generator's size and capacity, but other variables include the brand, fuel type, and labor for assembly and installation.

Generator costs can be broken down by type:

  • Portable or Emergency Backup Generators (1kW–7.5kW): $500 to $2,000

  • Partial-Home Generators (9kW–20kW): $2,000 to $6,500

  • Whole-House Generators (22kW–48kW): $5,000 to $18,000

To avoid paying for more power than you need, consider hiring an electrician to calculate the electrical load for your essential appliances. It is also recommended to get at least three quotes to find the best deal for your specific needs and budget.

If you have a transfer switch properly installed, the generator and main electrical power cannot feed the system at the same time. However, you should still shut off the power at your main circuit breaker panel before activating the generator. If you do that, you’ll simply need to shut off the generator and reset your circuit breaker once the local power comes back on.

You can determine what size generator you need for a transfer switch by matching the switch to the largest outlet on your generator. Larger generators can power up to 10 circuits, while most 5,000-watt generators can provide power to six circuits. So, if your generator’s largest outlet is 30 amps, you’ll need a 30-amp transfer switch.

You can expect a diesel generator to last for up to 30,000 hours of use, which works out to 20 to 25 years with the proper maintenance, of course. That depends on how much you use it, so a diesel generator used for emergencies a couple of times a year will last a lot longer than a generator that takes over for a faulty electrical grid every month for a day or two. 

To determine the right size generator for your house, you should calculate the total wattage of the appliances and devices you want to power during an outage. List all essential items, note their start-up wattages, and add them together.

Here are some typical wattage requirements for common appliances:

  • Refrigerator: 600 watts

  • Large dehumidifier: 700 watts

  • Large window air conditioner: 1,400 watts

  • Water heater: 3,000 to 4,500 watts

  • Electric furnace: 5,000 to 25,000 watts

A 7,500-watt generator might be sufficient for essentials like a refrigerator, freezer, well pump, and lighting circuits. However, for high-demand items like a water heater or furnace, a whole-home generator is a better choice. A portable generator may be enough if you only need to power a few critical items.

While home square footage can offer a rough estimate, it is not always a reliable indicator. For reference, here are some typical generator sizes based on square footage:

  • 1,000 sq ft: 6–9 kW

  • 1,500 sq ft: 7–10 kW

  • 2,000 sq ft: 10–14 kW

  • 2,500 sq ft: 12–16 kW

  • 3,000 sq ft: 16–20 kW+

For the most accurate sizing, consult a professional who can calculate your home's peak and average power consumption and recommend the optimal generator.

The Marion, IL homeowners’ guide to generator installs

From average costs to expert advice, get all the answers you need to get your job done.

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