How to Choose an HVAC Contractor in St. Louis

Choose an HVAC contractor by checking four things in this order: the license for your city or county, the permit the quote names, a written itemized proposal, and the pattern in the reviews. A low price or a friendly phone call replaces none of them. Missouri has no statewide HVAC license, so the check happens locally.

How do you check an HVAC contractor's license in St. Louis?

Ask every contractor for a license number for your jurisdiction, then verify it with the city or county. That includes us: ask any contractor, Kenan Corporation included, for the license number. We would rather you check than take our word.

Rules depend on where you live:

• City of St. Louis. Ordinance 70800 requires residential replacement or new heating and cooling units to be installed by a mechanical contractor licensed in the City, and that work needs a permit. The application fee is $25 and the Mechanical Section's number is 314-622-3313.
• St. Louis County. Mechanical licensing runs through the Department of Transportation and Public Works in Clayton. The Mechanical Licensing Clerk is at (314) 615-7096. A master mechanical license is reported to need 7,500 hours plus a county exam.
• Other municipalities. Rules vary. Ballwin, for example, pairs a county license with a city contractor license. Ask the local building office what applies in yours.

Who pulls the permit, and why does it matter?

The installing contractor pulls the permit, and the written quote should say so. St. Louis County requires a permit to install, alter, repair or replace heating, air-conditioning or duct systems, with county permits following the 2015 International Residential Code as amended. Filter changes and refrigerant recharges are not permit work.

A permit gets the job inspected by someone who does not work for the contractor. Be wary of anyone who suggests skipping it to save money. If the installer says the homeowner should pull it, ask why, and confirm with the local building office.

What should a written HVAC quote include?

A written quote is a comparison tool. Ask for these lines on every proposal.

1. Make, model and efficiency rating of each piece of equipment
2. Whether a load calculation was performed and what size it produced
3. Scope: what is replaced, what is reused (line set, thermostat, pad, plenum)
4. Duct modifications, if any
5. Permit and inspection, and who handles them
6. Removal and disposal of the old equipment
7. Payment schedule and total
8. Start date and a contact name

Insist on a load calculation before any new system is sized. Manual J, S and D are ACCA's names for load calculation, equipment selection and duct design, so ask which were done. We run a load calculation before sizing, and a clear, upfront quote comes before work starts.

How do you compare two quotes line by line?

Add the missing lines back before you judge the price. Angi's 2026 figures put a full St. Louis replacement anywhere from $4,755 to $11,888, so a wide gap between bids is normal and proves nothing alone. The table below is a made-up pattern, not a pair of real bids.

If A's price climbs to meet B's once the gaps are filled, you were comparing two different jobs. If B still costs more, ask what the difference buys. A higher efficiency rating has to repay its premium in lower bills, and the DOE minimum for a split AC in Missouri is only 13.4 SEER2. The same line-by-line habit works for a furnace installation or an AC installation quote.

How much weight should you give BBB grades and reviews?

Some. The BBB says customer reviews are not used in its letter grade, which rests on factors like complaint history and how a business responds. Accreditation is separate from the rating. Kenan Corporation holds an A+ BBB rating and is not BBB accredited.

For reviews, look for patterns across many entries rather than one dramatic story. We have 4.6★ from 29 Google reviews, which means not every review is a five, so read the critical ones for how the business responded. Check that dates are recent, that the work described matches yours, and that a reviewer names specifics.

From the field: explaining and options

Two reviews on the Google profile show the behaviors worth testing for. One Google reviewer, Candice F., wrote that Kenan is great at explaining things and giving you options. Another, Margaret S., said honesty and responsiveness is what they usually look for in a contractor, after learning a prior repair had not included the capacitor it was supposed to.

Those are the right tests. A good contractor explains the problem in plain language, offers options and itemizes what was done. The founder started Kenan Corporation in 2010, after 20-plus years at St. Louis area HVAC companies, because he wanted to bring honesty and fairness back to a trade that too often runs on commission goals.

When is a second opinion worth the delay?

Get one before a replacement, not before a repair. A replacement quote written without a diagnosis is a guess, so ask the first company what was tested and what failed. If the answer is vague, that is your cue to call another.

The trade-off is real. A second visit costs time, and some companies charge for a visit, so ask before you book. If the system is out in January or in a July heat wave, restore comfort first with the smallest safe repair and shop for a replacement afterward. Pressure to sign during an outage is the moment the red flags below matter most.

What are the red flags?

The FTC lists several, and they apply to HVAC as much as any home project.

• Pressure to decide today
• Demands for full payment up front, or cash only
• No written contract, or a contract missing a license number
• A price that is far lower than other bids, with vague scope
• Offers to skip the permit
• No references from similar projects

The FTC advises asking for at least three recent clients with similar jobs and calling them. It also advises proof of insurance, which any contractor should be able to provide on request.

Which questions should you ask on the first phone call?

Five questions sort contractors before anyone drives out.

• Which license applies at my address, and what is your number? A clean answer names the city or county that issued it, not a vague claim of being covered everywhere.
• Will you run a load calculation, or size from the old unit?
• Who pulls the permit, and who books the inspection?
• Is the visit charged, and will the proposal be itemized?
• How long does the written quote hold its price?

A contractor who answers these calmly before the visit is showing you how the job will go.

What should you keep after the installation?

Keep the paperwork that proves the job passed. File the final inspection record, the permit number, the model and serial numbers, the warranty registration and the itemized invoice together. Ask the installer for the refrigerant charge and airflow readings taken at start-up. A future buyer, a home inspector or a warranty claim will all ask for them. New split systems usually run on R-454B or R-32, so note the refrigerant on the invoice for whoever services it next.

Your shortlist: the next three steps

Collect two or three written quotes, verify each license with your city or county, and ask each company to name the permit and the load calculation. Homes in University City and Clayton sit in different jurisdictions from the City of St. Louis, so confirm which rules apply. Our HVAC contractor page lists the services we handle. We are open 24 hours, and you can ask for a clear, upfront quote at (321) 478-0693.