Buying a whole-home generator is one of the more complex purchases a homeowner makes — and one most people only do once. It's not like buying an appliance off a shelf: it involves sizing calculations, fuel choices, permitting, and a system that has to work correctly on the one day you actually need it. This guide walks through everything worth understanding before you talk to a salesperson — sizing, fuel type, transfer switches, what installation really involves, what ongoing ownership looks like, and the mistakes that trip up a lot of first-time buyers. If you're still deciding whether backup power is worth it at all, why DFW homes need backup power makes that case first.
This guide is written by HomeSafe. We are locally owned and operated, based in Fort Worth and working across DFW and North Texas, working under our own Texas Electrical Contractor License.
Generator size is measured in kilowatts (kW) — how much of your home's electrical load it can support at once. Getting this right matters more than almost any other decision in the buying process.
(Each tier builds on the one below it — the larger sizes cover everything the smaller ones do, plus more.)
Powering a business rather than a home? Our commercial generator installation page covers systems sized to commercial and industrial load.
(Running watts, for planning purposes — startup/surge watts run 2-3x higher for motor-driven appliances, and your actual sizing needs to account for both, not just running load)
| Appliance | Running Watts |
|---|---|
| Central AC (3-ton) | ~3,500W |
| Central AC (4-ton) | ~4,500W |
| Window AC (10,000 BTU) | ~1,200W |
| Refrigerator | ~700W |
| Electric range/oven | ~5,000W |
| Electric water heater | ~4,000W |
| Well pump (1 HP) | ~1,000W |
| Sump pump (1/2 HP) | ~800W |
| Washing machine | ~1,000W |
| Electric dryer | ~5,400W |
| EV charger (Level 2) | ~7,200W |
| Garage door opener | ~500W |
| Security system | ~50W |
An undersized generator doesn't just run "a little tight" — it overloads and shuts down, sometimes taking out a circuit mid-outage, which defeats the entire point of having backup power. The most common cause isn't underestimating your appliances' everyday power draw — it's underestimating startup (surge) watts. Motor-driven appliances like AC compressors and well pumps can draw 2-3x their running wattage for a few seconds when they kick on, and your generator has to handle the highest single surge on top of everything else already running.
An oversized generator isn't just a bigger up-front cost for capacity you'll rarely use — it also runs less efficiently at partial load, burning more fuel over its lifetime than a correctly sized unit would. Bigger isn't automatically better; correctly sized is better.
The only real fix for both: a proper load calculation done by someone qualified to do it, not a rough guess based on square footage alone. Our guide to what size generator you need walks through that calculation step by step.
Most whole-home standby generators run on natural gas or liquid propane (LP), and the right choice depends on what's actually available at your home and how you weigh a few real tradeoffs:
Neither is objectively "better" — it comes down to what's available at your property and how you weigh fuel-supply independence (propane) against installation simplicity and no tank management (natural gas). Your HomeSafe specialist will walk through both during your free consultation. Fuel type also affects long-term running cost — our guide to what affects home generator cost covers that side in detail.
A generator by itself doesn't power your home — the transfer switch is what actually connects it, and it's not optional for a true standby system.
The standard for a whole-home standby system. It continuously monitors your utility power, detects an outage, signals the generator to start, waits for stable output, and then automatically transfers your home's power source — typically within 10-20 seconds, with no action required from you. This is what "automatic" standby power actually means.
Cheaper, but requires you to physically act — flipping switches or connecting the generator yourself during an outage. This isn't the same thing as a whole-home automatic standby system, and it's worth being clear-eyed about that difference before assuming "generator" and "automatic backup power" mean the same purchase.
For homes where the full electrical load exceeds what's practical or affordable to back up entirely, a load management (load-shedding) system lets a smaller generator support a larger home by automatically prioritizing essential circuits and temporarily shedding non-essential ones (like a second AC unit) when demand peaks. This can be a smart way to right-size a system for a larger or higher-demand home without paying for maximum simultaneous capacity you rarely actually need at once.
Transfer switch installation is part of our electrical services work. For the full outage-to-transfer sequence explained end to end, see how a standby generator works. If you're still weighing a portable unit instead, standby vs. portable generators covers that comparison directly.
Standby generators are quieter than most people expect — typically in the 60-70 decibel range during operation, roughly comparable to a running dishwasher or a normal conversation, and similar to a central AC condenser unit. This is a real consideration on tighter lots or in HOA communities, but it's not the loud, portable-generator-style noise many people picture (portable units commonly run 70-90+ decibels). Placement still matters, and your installer should account for it.
Manufacturers generally recommend professional service about once a year (or roughly every 200 operating hours), plus an early oil and filter change after the first 25 hours of run time, and periodic battery replacement (typically every 2-3 years). This isn't optional housekeeping — skipping documented maintenance can affect what's covered if something goes wrong, since manufacturers expect a maintained system. See what's included in generator maintenance for a full breakdown of a professional service visit, or our generator service and repair page if you need work done now.
Warranty terms genuinely vary by brand, and it's worth comparing them directly rather than assuming they're all the same:
| Generac | 5-Year Limited standard warranty (Generac periodically runs promotional extended-warranty offers — ask what's currently available) |
|---|---|
| Kohler | 5-Year Premium Limited, which includes dealer travel coverage for service calls |
| Champion | 10-Year Limited plus free lifetime technical support — the longest standard warranty of the three brands HomeSafe installs |
With normal residential use (exercise cycles plus occasional real outages) and proper maintenance, a standby generator can reasonably be expected to last 20-plus years before major overhaul or replacement becomes a consideration. For the broader return-on-investment case, see is a whole-home generator worth it?
Whether you get a quote from HomeSafe or anyone else, a complete written quote should specify:
A vague quote that skips most of these isn't necessarily a bad installer — but it's worth asking for the specifics before you commit. For more on what actually drives the numbers in a quote, see our guide to generator installation cost.
Want more detail? Our generator installation service page covers what we handle and what to expect on install day.
HomeSafe installs Generac, Kohler, and Champion systems — we're not locked into recommending one brand over another, so the guidance you get is based on your home, not our inventory. See our full brand comparison for a detailed breakdown of how the three compare, or browse our full standby generator lineup across all three brands.
America's #1 selling home standby brand — the widest kW range HomeSafe installs, 18kW through 150kW.
Explore Generac →
The quietest of the three at comparable outputs, with 200-mile warranty travel coverage.
Explore Kohler →
The longest standard warranty of the three — 10 years, plus free lifetime technical support.
Explore Champion →It's not a same-day purchase. Between the initial assessment, permit approval, and scheduling, the full process commonly takes several weeks from order to activation — the installation work itself is typically completed in one to two days once permits are in hand.
In almost every municipality, yes — because the work involves both electrical and (for most installations) gas connections. Your installer should handle this for you rather than leaving it to you to navigate. Our guide to generator permits in Texas covers requirements county by county.
Not safely, and in most areas not legally. Standby generator installation involves licensed electrical work, gas connections, and code-required inspections — this isn't a do-it-yourself weekend project.
With proper annual maintenance, 20+ years of service life is a reasonable expectation for most residential standby generators.
No — see Part 1 above. Oversizing costs more up front and runs less efficiently at partial load. Correctly sized beats maximally sized.
If your generator is fueled by natural gas and your gas utility is disrupted (which can happen during a severe storm that damages infrastructure), your generator can be affected too. This is one of the real tradeoffs worth discussing against a propane system, which doesn't depend on utility gas delivery at all.
A real load calculation, an honest brand recommendation, and a written quote — with no obligation.