HVAC Contractor in St. Louis, MO

The work falls into four groups, and each one has its own page on this site.

• Repair. Finding why a system stopped heating or cooling, then fixing the failed part. See AC repair, furnace repair and heat pump repair.
• Replacement and installation. Sizing and setting new equipment when repair no longer pays. See AC replacement, furnace replacement and heat pump installation.
• Boilers and ductwork. Hot water and radiator systems in older houses, plus duct repair and rebuilds. See boiler service and duct repair and replacement.
• Maintenance and air quality. Seasonal checks, filtration and thermostat work. See AC maintenance, furnace maintenance and indoor air quality.

Kenan Corporation serves home and business owners, residential and light commercial, and the commercial HVAC page covers the business side. For every job, we diagnose before replacing parts, explain the problem in plain language and give a clear, upfront quote before work starts.

No heat in a cold snap or no cooling at 90°F is a safety problem for children, older adults and pets. The National Weather Service logged 49 days at or above 90°F in St. Louis in 2025. If your system is down now, call, and read the emergency HVAC page for what to do while you wait.

Water heaters and drain cleaning

Kenan Corporation's business listings also name water heater installation and drain cleaning. Those jobs have no page on this site yet. Call and describe the job, and you will get a straight answer on whether we take it.

Your address decides. Missouri has no statewide HVAC or mechanical contractor license, so cities and counties issue their own (Contractor License Requirements, 2026). A City license does not cover county work, according to Start Business By State (2026), and the reverse holds too.

Inside the City of St. Louis, Ordinance 70800 requires residential replacement and new heating and cooling units to be installed by a mechanical contractor licensed in the City. The Mechanical Contractors Board of Examiners oversees those contractors, and the City adopts the 2018 International Mechanical Code. The Mechanical Section answers questions at 314-622-3313.

In St. Louis County, mechanical licensing runs through the Department of Transportation and Public Works at 41 S. Central Ave. in Clayton. The Mechanical Licensing Clerk is at (314) 615-7096. A master mechanical license is reported to need 7,500 hours of experience plus a county exam (Start Business By State, 2026).

Municipal rules add a layer. Ballwin requires an active St. Louis County license in the contractor's field plus a city contractor license, according to the City of Ballwin. For most other towns, call the local building office before you sign.

Ask every contractor you consider for the license number that applies to your address, Kenan Corporation included. Then confirm it with the issuing office. A number that will not check out is your answer.

Yes, in most cases. The City of St. Louis requires a permit for replacement heating and cooling units, and the application fee is $25 (City mechanical permit fees page). St. Louis County requires a permit to install, alter, repair or replace heating, air-conditioning or duct systems, following the 2015 International Residential Code as amended for one- and two-family homes. Changing a filter or recharging refrigerant is not permit work.

The installing contractor pulls the permit, not the homeowner. That makes it a quote line to confirm, not a favor to hope for: ask who files it, what the fee is and who schedules the inspection. In Creve Coeur, for example, a licensed St. Louis County mechanical contractor pulls the permit and the city inspects afterward (City of Creve Coeur).

When the job ends, ask for the inspection record. A permit with no final inspection means no one outside the contractor has checked the work. Our furnace replacement and AC replacement pages walk through the same steps for each system.

Angi reports that a full HVAC replacement in St. Louis costs $4,755-$11,888, with a $7,133 average (Angi, 2026). Labor runs $75-$150 per hour, and labor makes up roughly $1,500-$5,000 of a full replacement. These are market figures, not a Kenan Corporation quote.

The lifespan column comes from contractor sources, so treat it as a planning range. Where the table says no local figure was verified, we left the cell honest instead of guessing. Our furnace replacement cost guide breaks down what moves the price.

A usable quote itemizes five things:

• Equipment make, model and SEER2 rating or AFUE
• Labor, stated as a total or an hourly rate
• The permit and inspection, and who handles each
• The refrigerant type
• Any warranty terms, in the contractor's own words

If a line is missing, ask for it before comparing totals. A lower bottom line often leaves out the permit or the inspection.

A replacement follows six steps, and a good contractor tells you which one you are in.

1. Diagnose. Confirm what failed, note the age and read the model and serial plate.
2. Size the system. Run a load calculation so new equipment fits the house instead of copying the old unit.
3. Quote. Put equipment, labor, permit and inspection in writing before work starts.
4. Permit. The installing contractor files it and waits for approval.
5. Install. Set the equipment, connect the lines and ducts, then test the system and check what else is working.
6. Inspect. The final inspection closes the permit, and you keep the record.

Calling first saves time. Send the symptom, your ZIP code and a photo of the model and serial plate, and the quote comes back firmer. We offer same-day service when the schedule allows, and we are open 24 hours.

It depends on the repair quote set against the system's age. Furnaces, air conditioners and heat pumps commonly last 15-20 years with routine maintenance, according to contractor sources. A $300 capacitor on a 12-year-old unit is an easy yes. A $2,500 compressor on a 17-year-old unit is a hard conversation.

Ask for the repair quote and a replacement quote side by side, then count the years the repair actually buys. One Google reviewer wrote that another company called for a new furnace without checking any parts, and Kenan Corporation found a capacitor and fixed it. Repair-first is the rule this company was founded on, so when the fix is a capacitor, that is what we say. The quiz below scores system age, symptoms and the repair quote.

Our guide to repairing or replacing an old AC works through the same decision with examples.

They make both seasons count, and they make the house itself part of the diagnosis. St. Louis sits in ASHRAE Climate Zone 4A, mixed-humid. In 2025, NWS St. Louis recorded 1,904 cooling degree days against a 1,713 normal and 4,100 heating degree days against a 4,433 normal. A system here works hard twice a year, which is why we recommend one tune-up before each season.

Housing age matters as much. The median home in the City of St. Louis was built in 1938, against 1979 for Missouri and 1981 for the U.S. (ACS via Neilsberg), and 58.4% of City homes, 98,845 of 169,310, were built in 1939 or earlier (Point2Homes). Those houses often have boilers, radiators, tight chases and ducts added decades after construction.

In those homes, the first step is an inspection of the boiler and ducts, followed by a load calculation before equipment is sized. It is an inspection, not an upsell. The result might be keeping the boiler, adding a ductless mini-split where ducts are poor, or rebuilding runs with a duct repair.

Ameren Missouri's rebates are real and the federal credit is gone. Ameren's 2026 chart runs from January 1 to December 31, 2026, and HVAC rebates sit under tier 4 of its Pay As You Save (PAYS) program. It lists $2,000 per system for air-source heat pumps at 15.2+ SEER2 in dual-fuel, electric-resistance-replacement and no-existing-central-system cases, $500 per ton for mini-splits at 19+ SEER2, and $5,000 per system for ground-source units at 23+ EER2.

Work must go through a participating contractor, and that contractor submits the paperwork. Ameren's Find a Contractor tool lists them. Kenan Corporation makes no claim to be on that list, so check it for any firm you hire. Confirm eligibility in writing before you sign, because a 2027 chart may differ.

The federal 25C credit does not apply to property placed in service after December 31, 2025, according to the IRS. Do not budget for it. Missouri's HEAR and HOMES programs have about $75 million each allocated, but the Missouri Department of Natural Resources was still procuring in mid-2026 and no launch was confirmed. Check dnr.mo.gov/energy before you count on either.

Run four checks in order: the license for your address, the permit plan, the written quote and the proof behind the company. Reviews and BBB status come last, as support. BBB says customer reviews are not used in its letter grade, so read both separately.

A license check takes five minutes:

1. Work out whether your home sits in the City of St. Louis or in St. Louis County.
2. Ask the contractor for the license number that applies there.
3. Look the number up with the City's Mechanical Section or the County's Mechanical Licensing Clerk.
4. Get the permit plan, including who files it, written into the quote.

Do not skip the lookup. It is the only step that confirms the paper behind the name.

Here is the proof we can show. Kenan Corporation holds a 4.6★ rating from 29 Google reviews, checked in October 2026, and an A+ BBB rating. We are not BBB accredited. Our reviews page shows every written review, including the critical ones.

Why Kenan Corporation for a first call? Because the habit is diagnosis first. One Google reviewer described a failed capacitor that another company had skipped past, and another called us "Great at explaining things and giving you options." Kenan Bruce Martz founded the company in 2010 after more than 20 years at St. Louis area HVAC companies, because he disliked hard-sell pitches and commission goals. Owner Kenan Perkins, who studied at Ranken Technical College, leads it today. Read more on the about page.

We serve St. Louis County, St. Charles County, Jefferson County and Franklin County from a base near Spanish Lake. Drive times run from about 5 minutes in Spanish Lake to about 35 minutes in Clayton in normal traffic, and they are not arrival promises. University City, Creve Coeur and Kirkwood each have their own page, and the service areas page lists the rest. Call first if you are at the edge of that range.

Permit and license rules change at city lines, so check your town before you compare quotes. Drive times run from our base near Spanish Lake in normal traffic and are not arrival promises.

• Florissant, about 20 minutes: the city lists furnace and AC installation as permit work, and construction permits can take 7 to 10 days, so build that wait into a replacement date.
• Bridgeton, about 30 minutes: St. Louis County Public Works issues the mechanical permits here, not the city, so the installer's county license is the one that matters.
• Hazelwood, about 25 minutes: the city has adopted the 2021 International Mechanical Code, and its Code Enforcement office handles the inspection side.
• University City, about 30 minutes: the city runs its own permit office at City Hall on Delmar Boulevard, and its online portal lists the building and mechanical permit forms.
• Maryland Heights, about 35 minutes: the city issues residential mechanical permits and allows a like-for-like furnace or condenser swap without plans; the county handles commercial and multifamily work.
• Clayton, about 35 minutes: mechanical permits for replacement furnaces, AC and ductwork go through the city's online portal under the 2021 International Mechanical Code.
• Creve Coeur, about 40 minutes: a county-licensed mechanical contractor pulls the permit, and the city inspects afterward.
• Maplewood, about 40 minutes: the city does not issue mechanical permits, so a furnace or central AC replacement is permitted through St. Louis County Public Works.
• Kirkwood, about 50 minutes: every contractor needs a Kirkwood license, and replacement permits are filed online under that license.
• Ballwin, about 55 minutes: a contractor needs an active St. Louis County license in the field plus a Ballwin contractor license before a permit is issued.

Farther out in St. Charles, Jefferson and Franklin counties, call first to confirm scheduling and the local permit office. Our service areas page lists every town.