Whole-Home Generator Installation in O'Fallon, MO
Never lose power again with a whole-home standby generator. As Generac certified installers, we provide complete backup power solutions for Missouri homes throughout St. Louis and St. Charles County. We serve all of O'Fallon, from Fort Zumwalt Park to the neighborhoods toward St. Peters.
O'Fallon homes
O'Fallon's newer subdivisions mostly have 200-amp service, while homes in the older neighborhoods closer to downtown can still be on 100 or 150 amps with their original panels.
Permits and utility
- Permit: pulled with St. Charles County or the City of O'Fallon, whichever has jurisdiction, and inspected before we finish.
- Utility: Ameren Missouri or Cuivre River Electric Cooperative, depending on your address. We schedule any disconnect, reconnect or meter work.
- ZIP codes: 63366, 63368, 63376
What it costs in O'Fallon
Essential Coverage (10-14kW)
$5,000–$8,000
- 10-14kW Generac generator
- Automatic transfer switch (load-shedding)
- Concrete pad installation
- Gas line connection (up to 25 feet)
- Electrical connection to panel
Powers essential circuits: fridge, lights, sump pump, furnace, select outlets
Whole-Home (18-24kW)
$10,000–$16,000
- 18-24kW Generac Guardian
- Whole-home automatic transfer switch
- Concrete pad installation
- Gas line connection (up to 50 feet)
- 200A panel connection
Powers entire home including A/C, electric appliances
Large Home (26-48kW)
$18,000–$30,000
- 26-48kW commercial-grade generator
- Whole-home transfer switch
- Reinforced concrete pad
- Extended gas line installation
- Potential service upgrade
All-electric homes, large properties, pools, workshops
Typical ranges. Your written quote follows a free on-site assessment.
How the job goes
Load Analysis
We calculate your power needs by listing everything you want to keep running during an outage: HVAC, refrigerators, sump pump, lights, medical equipment, garage doors, etc. This determines the generator size you need.
Site Survey
A technician visits your home to determine optimal generator placement (meeting code setback requirements from windows and property lines), plan gas line routing from your meter, and assess electrical connection to your panel.
Detailed Quote
You receive a comprehensive quote covering the generator, transfer switch, concrete pad, gas line installation, electrical connection, and all permits. We explain options for whole-home vs. essential coverage.
Permits & Coordination
We pull electrical and gas permits from your municipality. Generator installations require permits and inspection. We coordinate with your gas utility for the new gas line connection.
Site Preparation
We pour a concrete pad (or install a composite pad) sized for your generator, ensuring proper drainage and level installation. The pad must cure before generator placement.
Whole-Home Generator Installation questions from O'Fallon
Do you handle the permit for whole-home generator installation in O'Fallon?
Yes. We pull the permit with the office that has jurisdiction at your address, St. Charles County or the City of O'Fallon, and schedule the inspection. The permit is included in our quote.
Who is the utility for O'Fallon homes?
O'Fallon is served by Ameren Missouri or Cuivre River Electric Cooperative, depending on your address. When the work needs the power disconnected or a meter changed, we coordinate it with the utility for you.
Which parts of O'Fallon do you serve?
All of O'Fallon (63366, 63368, 63376) and the surrounding area, including St. Peters, Lake St. Louis, Wentzville, Dardenne Prairie.
What size generator do I need?
It depends on what you want to power. A 22kW generator typically covers most homes. We'll perform a load analysis to recommend the right size.
How quickly does it start?
Automatic standby generators start within 10-30 seconds of detecting a power outage, before your refrigerator even knows the power went out.
What fuel type is best?
Natural gas is most convenient if available: unlimited fuel during extended outages. Propane is excellent if you don't have natural gas service.
Do generators require maintenance?
Yes. Generators need annual maintenance: oil changes, filter replacement and testing. We install generators but don't service them, so we'll point you to the manufacturer's authorized service dealer for maintenance.
More from First Choice Electric
See everything about whole-home generator installation, or all our electrical services in O'Fallon.
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