Commercial HVAC Repair in St. Louis, MO

Commercial HVAC repair starts with the question of what the outage costs you each hour. A dead rooftop unit in an office means uncomfortable staff, in a shop it means customers who leave, and in a small restaurant it means a dining room and kitchen that cannot run. Kenan Corporation diagnoses the failed part, explains it in plain language and gives a clear, upfront quote before any work begins.

What does a failed HVAC unit cost a working business?

Downtime costs more than the repair when the space cannot operate. Three risks are worth naming before you call.

• Staff and customers. OSHA has no specific temperature standard for offices, but it recommends keeping them between 68 and 76°F and says employers must protect workers from temperature extremes.
• Lease duties. Your lease sets who repairs the equipment, who is told first and who pays. Missing a notice clause can turn a repair into a dispute.
• Repeat failures. The U.S. Department of Energy's FEMP guide reports that more than 55 percent of maintenance activity in the average facility is still reactive. Repeat breakdowns usually trace back to something a record or a scheduled visit would have caught.

A repair that also identifies what else is wearing out beats a quick patch.

What should you gather before you call?

Gather five things and the first visit goes faster. None of them require technical knowledge.

1. Symptom and start time. No cooling, no heat, noise, water, tripped breaker, or a fault code on the thermostat.
2. Unit location and access. Which roof or closet, where the hatch or ladder is, and who holds the key.
3. Nameplate details. A phone photo of the model and serial plate saves a trip.
4. Occupancy. When the space is empty, and whether customers or staff are present.
5. Lease contact. The landlord or property manager who must approve work or be told.

Which light commercial systems does this page cover?

This page covers repairs on the equipment that serves small commercial buildings. That means rooftop package units, split systems with an outdoor condenser and indoor air handler, and gas furnaces serving offices, shops and small restaurants. It is light commercial work, not large plant work.

If your building runs a central plant or chilled-water system, describe it when you call and ask whether it fits.

How does a repair visit run in an occupied building?

A visit in an open business is planned around the people in it, so tell us your hours. The steps follow the same sequence on every call.

1. Confirm the symptom and get access to the equipment.
2. Diagnose before replacing parts, from thermostat and controls to electrical parts, airflow and refrigerant.
3. Explain what failed and what the options are.
4. Give a clear, upfront quote before work starts, in a form you can forward to a landlord or manager.
5. Repair, run the system and check what else is working.

We are open 24 hours and offer same-day service when the schedule allows, so call early when the unit failed overnight. A Google reviewer who placed an emergency call wrote that the technician arrived within 12 hours, replaced the failed item and checked that everything else worked. That is the repair pattern on every call.

What a commercial repair visit covers

• Fault history from your staff and any codes on the controls
• Electrical, airflow and refrigerant checks on the failed unit
• Belt, filter and economizer checks on rooftop units
• A plain list of what failed and what to watch
• A clear, upfront quote before parts are ordered

What are the most common commercial repairs?

Most no-cooling and no-heat calls trace back to a short list of faults. The table shows where each one tends to hide.

What does a commercial repair cost in St. Louis?

The fault, the access and the hour set the price. Angi's 2026 range for St. Louis HVAC labor is $75 to $150 per hour, a market range and not our quote.

• The failed part, and whether it must be ordered
• Roof access: a fixed ladder, a hatch or a lift
• Unit age, refrigerant type and parts availability
• The hour of the visit, so ask about after-closing work

Ask for parts, labor and refrigerant listed separately, and whether the price is hourly or flat.

The compressor row is where honesty matters most. A very old unit with a failed compressor deserves a comparison of repair and replacement costs, and we would rather repair your system than pressure you into a new one.

Which records should you keep after each repair?

Keep one file per unit. It pays for itself the second time something breaks.

File the invoice and quote, the model and serial numbers, what failed and what was replaced, the date and any permit number. The next technician starts with the history instead of guessing.

Read any manufacturer's warranty yourself before approving a part, since terms can depend on who installed or serviced the unit.

Which permits and licenses apply to commercial repairs?

St. Louis County says a mechanical permit is needed to install, alter, repair or replace a system, and the work must be done by a contractor licensed for mechanical work. Commercial jobs add layers: Maryland Heights sends commercial mechanical permits to the county, Bridgeton runs occupancy inspections through city Public Works, and Florissant requires an occupancy permit before a business moves in.

The City of St. Louis Mechanical Section, at 314-622-3313, can say how commercial work is handled there. Ask any contractor, including us, which license your address requires.

Why Kenan Corporation for business HVAC repair

Our proof is the pattern in customer reviews, where we hold a 4.6★ rating from 29 Google reviews as of October 2026.

• Diagnosis before parts. A Google reviewer was told a furnace needed replacing, and the real fault was a capacitor, found and fixed.
• Honesty about the cause. Margaret S. wrote that a capacitor supposedly replaced by a prior person was not in the unit, and the technician advised the fan motor was going out.
• Open 24 hours. An overnight failure can be reported at any hour, with same-day service when the schedule allows.
• Home and business owners. The company serves both, and its founder started it in 2010 to bring honesty and fair dealing back to the trade.

We reach Hazelwood in about 25 minutes, Bridgeton in about 30 minutes and Maryland Heights in about 35 minutes from our base near Spanish Lake, in normal traffic.

Where we repair business systems

• Hazelwood: flat-roof packaged units serve offices and light-industrial spaces near the old Ford plant site.
• Bridgeton: the county issues mechanical permits and the city runs occupancy inspections, so a quote should say who files what.
• Maryland Heights: offices cool from packaged rooftop units, and the county, not the city, handles commercial mechanical permits.
• Florissant: a working rooftop or split system is a first-week item for a new tenant facing the city's occupancy inspection.
• Clayton: small office suites and retail spaces fit; a building with a chiller needs a call first.
• Creve Coeur: small suites off Olive Boulevard fit, while nearby hospital and laboratory systems are a different scale.
• University City: Delmar Loop shops and restaurants sit among apartment buildings making up about a third of units.
• Chesterfield: Chesterfield Valley's retail and light-industrial buildings along Olive Boulevard can file a separate city mechanical permit.

How do you stop the same repair from coming back?

A planned visit twice a year catches belts, filters, coils and drains before they fail on a hot afternoon. Studies cited in the DOE's FEMP guide put the savings from preventive maintenance at as much as 12 to 18 percent over reactive maintenance. Read our page on commercial HVAC maintenance for what a scheduled agreement should list, and see the rooftop unit service page if the unit is near the end of its life.