Franktown, CO Standby Generator Installation & Maintenance Tips

Estimated Read Time: 14 minutes

Choosing the right whole house generator size is not guesswork. It is careful whole house generator sizing based on your real loads, fuel supply, and code rules. In Denver, outages often hit during winter storms or summer lightning. The right kW means heat, lights, Wi‑Fi, and medical devices stay on without tripping breakers or wasting fuel.

Why Generator Size Matters More Than You Think

Undersize a generator and you get dim lights, tripped breakers, and cold rooms when you need power most. Oversize it and you pay more up front and burn extra fuel. A well-sized standby unit should start your biggest motors, run essential circuits, and allow a modest cushion for safety and future loads. The goal is smooth, automatic comfort without overspending.

Two hard facts guide the process:

1. Code and permitting: In most Front Range cities, generator installs require both building and fire department approvals. Our team handles permitting, inspections, and code compliance so your system passes the first time.
2. Fuel and capacity: Natural gas and propane are the most common fuels for residential systems up to about 22 kW. Diesel is used less often for homes but remains an option in specific cases.

Step 1: Decide What You Want to Power

Start with priorities, not products. Make a list of rooms and systems you must keep on during an outage.

• Always-on essentials:
  • Furnace or boiler controls and blower
  • Refrigerator and freezer
  • Sump pump, well pump, or medical devices
  • Wi‑Fi, lighting, outlets in key rooms
• Nice-to-have items:
  • Range or microwave
  • Garage door opener
  • Washer and limited outlets in bedrooms
• High-draw appliances to evaluate carefully:
  • Central AC or heat pump
  • Electric water heater
  • Electric oven, EV charger, hot tub

Pro tip: Many families power one HVAC system, the kitchen, internet, and basic lighting. Large all-electric homes or dual HVAC systems may require more capacity.

Step 2: Gather Load Numbers the Right Way

Knowing nameplate wattage is a start, but motors need more power to start than to run. That extra demand is called starting or inrush current.

• Running watts: The power a device uses while operating.
• Starting watts: The brief surge needed for motors to start.

How to collect data:

1. Read appliance labels or manuals for amps and volts. Multiply to get watts (amps × volts = watts).
2. Check your electrical panel for breaker ratings and dedicated circuits.
3. Use recent utility bills to understand typical usage, then layer on starting loads for HVAC and pumps.

Step 3: Understand HVAC Impact on Sizing

Air conditioners and heat pumps drive sizing decisions more than any other load. As a general guide from our field experience:

• Homes with a 3‑ton AC unit often pair well with about an 11 kW generator when covering essentials plus AC.
• Homes with a 5‑ton AC system may require at least a 20 kW unit if the AC must run with other key circuits.

These are starting points. High-efficiency models, soft starters, and load management can reduce the required size while preserving comfort.

Step 4: Account for Altitude and Weather in the Denver Area

Engines lose power at elevation. Many air‑cooled generators derate roughly 3 to 4 percent per 1,000 feet above sea level. At Denver’s 5,280 feet, output can drop about 15 to 20 percent compared to sea level. Cold snaps and summer heat also affect starting loads.

What this means for you:

• A unit labeled 20 kW at sea level may deliver closer to 16 to 17 kW here.
• Proper derating is crucial to avoid nuisance trips during the first big storm.

Step 5: Choose Fuel Type With Real‑World Tradeoffs

Most Colorado homeowners choose natural gas or propane for standby generators up to 22 kW. Each fuel has pros and cons.

• Natural gas:
  • Unlimited supply from the utility, no tank refills
  • Slightly lower BTU content than propane per unit volume
  • Requires adequate gas meter and piping capacity
• Propane:
  • Stored onsite, reliable in gas utility outages
  • Higher energy per unit than natural gas
  • Requires tank sizing and safe placement
• Diesel:
  • Strong torque for heavy loads
  • Onsite fuel storage and cold-weather maintenance required

We evaluate meter capacity, line length, and regulator sizing during your site visit to ensure proper fuel flow under peak load.

Step 6: Decide Between Whole‑Home vs. Managed Circuits

You can power the entire panel or select circuits.

• Whole‑home approach:
  • Larger generator, simplest user experience
  • Best with gas heat and modest electric loads
• Managed or essential circuits:
  • Smaller generator with load-shedding modules
  • Prioritizes furnace, fridge, lights, and internet

Load management technology can stagger large loads like AC so you avoid oversizing while keeping comfort.

Step 7: Sizing Math in Plain English

Here is a practical way to estimate your size range before a professional assessment.

1. Tally running watts for essentials.
2. Add starting watts for the largest motor load (often AC or well pump).
3. Apply an altitude derating factor of about 15 to 20 percent for the Denver metro.
4. Add a 15 percent headroom buffer for winter or summer extremes and future devices.

Example:

• Essentials total: 6,000 W running
• Largest motor starting: +4,000 W
• Subtotal: 10,000 W
• Altitude derate 15 percent: plan for 11,500 W capacity
• Headroom 15 percent: about 13,200 W target

In this case, a 14 to 16 kW unit often fits, assuming no large electric range or water heater during outages.

What an Automatic Transfer Switch Does for You

An automatic transfer switch, or ATS, is the brain of the system. It monitors utility power and, when an outage hits, starts the generator and transfers the load within seconds. Power returns just as smoothly when the grid is back. We select and size the ATS to match your service amperage and desired circuits.

Permits, Codes, and Placement Rules You Should Know

Safety and compliance are nonnegotiable. Local building and fire authorities review clearances, fuel lines, and electrical work. We handle all permitting, inspections, and code requirements so you do not have to.

Typical considerations:

1. Setbacks from windows and openings for carbon monoxide safety
2. Proper pad, anchoring, and snow shedding in winter
3. Gas line sizing, regulator placement, and electrical bonding
4. Noise ordinances and neighbor considerations

Most installations complete in one to two days once permits and utility coordination are ready.

Professional Sizing Walkthrough: What to Expect From Bell

We start with an in‑home consultation to evaluate your usage and discuss priorities. Then we perform a site inspection to determine optimal placement and fuel access. You receive a clear, no‑pressure quote that includes the generator, ATS, permit handling, trenching or piping, electrical work, startup testing, and cleanup. Old equipment removal is covered for replacements.

Our installations include a satisfaction guarantee with a one‑year labor warranty. We also provide free second opinions on large installation projects so you can compare options with confidence.

AC Starting Challenges and Smart Fixes

If AC is critical, we evaluate:

• Locked rotor amps (LRA) for your compressor
• Breaker size and wire run
• Whether a soft‑start module can cut the starting surge

A properly chosen soft‑start can reduce inrush current, allowing a smaller generator to run the system without lights dimming when the compressor kicks on.

Gas Meter and Propane Tank Sizing Made Simple

Generators are hungry at full load. We calculate cubic feet per hour for natural gas or BTU draw for propane and ensure your meter, regulator, and piping match the demand. If the existing meter is undersized, we coordinate with the utility or size a propane tank that meets runtime goals. Your options might include 250, 500, or 1,000 gallon propane tanks depending on outage duration targets.

Runtime Expectations and Outage Strategy

Not every appliance must run at once. A good strategy prioritizes comfort and safety without oversizing.

• Daytime: lights, outlets, internet, fridge, office, and one HVAC system
• Night: reduce large loads, keep heat, fridge, and essential outlets

Load management and homeowner habits make a 14 to 22 kW range viable for many homes across Denver, Aurora, Lakewood, Thornton, and Arvada.

When a Whole‑Home 22 kW Makes Sense

Choose the upper range when:

1. You have a 200‑amp service with many electric appliances
2. You need central AC or a heat pump running with other loads
3. You rely on medical equipment and cannot risk shedding
4. You want true set‑and‑forget operation with minimal manual management

When a 11 to 14 kW System Is the Sweet Spot

A smaller unit can be ideal if:

1. You have gas heating and water heating
2. You are comfortable managing oven, dryer, or EV charging during outages
3. You install a soft‑start on AC or use a mini‑split for key rooms

Replacement vs. First‑Time Installation

Replacing a tired generator is often faster. We remove the old unit, reuse viable infrastructure, and commission the new system. First‑time installs need utility and permit coordination, slab or pad, fuel routing, and panel work. Either way, commissioning includes start‑up, ATS testing, and homeowner orientation so you know exactly how the system behaves.

Maintenance: Keep It Ready, Not Dusty

A standby generator should be ready every day, not just on day one. Your unit will perform weekly self‑tests and should receive periodic service for oil, filters, plugs, battery health, and enclosure checks. We provide follow‑up on installation and setup and can coordinate maintenance solutions so your system is always ready for the next storm.

Membership perks through our Bell Perks Club deliver savings, priority scheduling, and extended warranty benefits on qualifying services across our electrical, HVAC, and plumbing teams.

Insurance and Property Value Benefits

Many insurance companies offer premium discounts when you install a code‑compliant standby generator. In our experience, whole‑house systems can also increase property value by improving resilience. We provide documentation and photos for your records and for insurance when requested.

Local Insight: Sizing for the Front Range

Along the Front Range, wind, wet snow, and fast temperature swings create unique outage profiles. Frozen condensate drains can trip safeties, and long gas runs at altitude need careful regulator planning. Our Denver team sizes with these realities in mind and designs placements that respect snow shedding from roofs and side yards in neighborhoods like Westminster, Centennial, Highlands Ranch, Castle Rock, and Broomfield.

The Bell Process, Step by Step

1. In‑home consultation to define loads and priorities
2. Site inspection for placement, gas access, and clearances
3. Transparent, flat‑rate proposal with options
4. Permit management with building and fire departments
5. Professional installation, fuel and electrical work, startup, and cleanup
6. Commissioning with ATS testing and homeowner training
7. Ongoing support and follow‑up on installation and setup

Quick Sizing Checklist You Can Use Today

• List essentials and high‑draw appliances
• Note AC tonnage and whether a soft‑start is installed
• Record fuel type and meter or tank details
• Check for electric range, dryer, water heater, or EV charger
• Consider altitude derating and a 15 percent headroom buffer
• Plan whole‑home vs. managed circuits and ATS size

Bring this list to your consultation and we will translate it into the right kW, fuel, and ATS combination for your home.

What You Get With a Bell Installation

• Licensed electricians and installers
• Permits, inspections, and code compliance handled
• Automatic transfer switch sized to your service
• One‑year labor warranty on new installs
• Free second opinions on large projects
• Respect for your home with shoe covers and thorough cleanup

Your result is a quiet, reliable, and safe backup system that starts automatically and powers what matters within seconds.

Frequently Asked Questions

How do I calculate the right generator size for my house?

List essential loads, add starting watts for the largest motor, apply a 15 to 20 percent altitude derate for Denver, then add about 15 percent headroom. A professional load review confirms the final size and accounts for fuel flow and code rules.

Do I need an automatic transfer switch?

Yes. An ATS monitors the utility and switches power to the generator within seconds during an outage. It also switches back automatically when the grid returns, protecting your appliances and simplifying operation.

How long does installation take?

Most residential installations finish in one to two days once permits and utility coordination are complete. We handle building and fire department approvals, placement, fuel lines, electrical work, testing, and cleanup.

Can a generator run my central AC?

Often yes, with proper sizing. A 3‑ton AC may pair with about 11 kW, while a 5‑ton may need 20 kW or more. Soft‑start modules can reduce inrush current and help smaller generators start compressors reliably.

What fuel is best for a home standby generator?

Natural gas and propane are most common for homes up to about 22 kW. Natural gas offers continuous supply. Propane provides onsite storage. We size meters, regulators, or tanks so fuel delivery matches generator demand under load.

Final Takeaway

Whole house generator sizing is about matching real loads, altitude, and fuel capacity to a safe, code‑compliant system. In the Denver area, we design for elevation, weather, and local permit rules so your home stays comfortable when the grid fails. Ready to get your custom sizing and quote in Denver or nearby cities?

Get Your Sizing Consultation Today

Call Bell Plumbing, Heating, Cooling & Electrical at (720) 740-0350 or visit https://bellplumbing.com/ to schedule. Ask for a free second opinion on large installation projects. We serve Denver, Aurora, Lakewood, Thornton, Arvada, Westminster, Centennial, Highlands Ranch, Castle Rock, and Broomfield.

About Bell Plumbing, Heating, Cooling & Electrical

Since 1926, Bell has helped Denver‑area homeowners with licensed electrical, HVAC, and plumbing services. We offer flat-rate pricing, NATE-certified techs, BBB listing, and a 100% satisfaction guarantee backed by a one-year labor warranty on new installs. Expect tidy work, shoe covers, and clear options. From transfer switches to panel upgrades, we design safe, code-compliant solutions that fit your home and budget.