If you’re reading this because a storm forecast changed your plans, I get it. I’ve spent more late nights than I can count helping facility managers, contractors, and homeowners vet backup generator suppliers.
Here’s what to look for in a backup generator supplier, organized as a checklist. It’s for anyone comparing whole house generator suppliers or planning a Briggs & Stratton generator installation. It’s not every possible consideration—it’s the six things that actually matter when you need the generator to work on day one.
If you’re a dealer or contractor evaluating a brand to carry, the same list applies. Warranty support and parts availability become even more important when you’re putting your name on the installation.
Before You Start
You don’t need to become a generator expert before calling a supplier. You do need to know two things:
- What you want to power during an outage—probably a forced-air furnace, fridge, well pump, and some lights.
- Whether you’re installing a portable unit or a permanently installed standby unit.
That second one matters more than you’d think. A standby unit involves permits, gas lines, and an automatic transfer switch. A portable unit can be a bigger extension cord. The checklist below is mostly for standby installations.
Step-by-Step Supplier Checklist
1. Ask for the transfer switch plan before you talk hardware
The transfer switch is where the generator connects to your house wiring. If that’s wrong, the whole installation is wrong—and a generator can become a safety hazard instead of a power source.
Ask every supplier, in writing: “What transfer switch do you recommend, and is it included in the quote?” Automatic transfer switches cost more than manual ones, but if you want power to come on without walking outside in a storm, that’s what you need. In March 2024, I had a client who found out after delivery that the “complete” quote didn’t include the switch at all. We scrambled for one with 36 hours to go. It worked, but nobody needed that stress.
2. Confirm who handles permits and inspections
Most jurisdictions require a permit for a permanent generator installation. The NEC covers optional standby systems in Article 702, and local amendments can add more. A good supplier will say, “We pull the permit and schedule the inspection.” That’s the answer you want. In other words, someone else owns the inspection.
If a supplier treats permits as optional, that’s a red flag. I am not saying every unpermitted install fails. But it puts the burden on you if anything goes wrong at resale or in an insurance claim.
3. Get the installation manual before you sign
This is the step most people skip. Ask the supplier to email you the installation manual for the exact model they’re quoting. You don’t need to read every page. You’re looking for:
- Clearance requirements from the house and windows
- Gas line size and pressure requirements
- Required service access space
- Warranty registration steps
If they can’t send you a manual, that’s not necessarily a deal-breaker—but it means you should slow down. “We don’t have the PDF” is a different thing from “I’ll send it after lunch.” Plus, it tells you whether they’ve actually opened the manual before.
4. Check fuel supply specs with a gas contractor
The surprise wasn’t the generator price. It was the gas line. I’ve seen more than one project where the generator was affordable but the natural gas line didn’t have enough capacity. That’s a cost nobody puts in the initial quote.
Ask the supplier: “What’s the gas consumption at full load? What minimum gas line pressure does this model need?” Then have a licensed gas fitter or plumber confirm your existing line can handle it. At least, that’s been my experience with residential standby projects—and it’s why I now ask for fuel data before recommending anyone buy anything.
5. Verify warranty terms and parts availability
Warranty terms can look identical and be different. Ask three questions:
- How long is the residential and commercial warranty?
- What’s covered—parts, labor, or both?
- Who do you call after installation for warranty service?
For a Briggs & Stratton generator, service network coverage can be excellent in some regions and thin in others. That’s fine. Just ask the supplier to name the local dealer who’ll actually do the warranty work. If they can’t name one, you’re the one who’ll be chasing service later.
6. Schedule the startup test and owner training
I always push for a startup test as part of the contract. The generator should be load-tested—power off the house, transfer to generator, run for a while, transfer back. There’s something satisfying about watching a whole-house unit start in ten seconds and hearing the fridge kick back on. That’s the payoff after all the paperwork.
I’ve coordinated maybe forty standby installations—give or take, I’d have to check the spreadsheet. The ones that went smoothly all had one thing in common: someone showed the homeowner how to do basic maintenance. Make sure your supplier walks you through the exercise schedule, the oil drain location, and how to silence alarms. You don’t need to know everything, but you need to know enough to not panic at 2am when the power blinks.
Mistakes I’ve Made So You Don’t Have To
Looking back, I should have asked for the gas line sizing earlier. At the time, I figured the supplier would handle it as part of the installation. They didn’t—it was a separate trade. The total cost came in maybe 20% higher than the quote—actually, it was closer to 18%, I’m mixing it up with another job. Either way, it was over budget and a week late.
If I could redo that decision, I’d get the gas contractor involved before signing. But given what I knew then, my choice was reasonable. Now, it’s step four on every checklist I send to clients.
Also, don’t assume “house generator supplier” and “whole house generator supplier” mean the same thing to every vendor. Some companies supply units only, some install, some do both. Ask directly: “Are you supplying, installing, or both?”
Bottom Line
The best whole house generator supplier is the one who makes installation boring—permits handled, transfer switch planned, fuel line checked, startup test passed.
An informed customer asks better questions and makes faster decisions.
I’d rather spend ten minutes on the phone explaining these steps than deal with a mismatched expectation after the hole is already dug.
