AC Repair in St. Louis, MO

AC repair in St. Louis comes down to one question: which part actually failed? We test the capacitor, contactor, fan motor, refrigerant circuit and drain before we recommend anything. That order matters, because one Google reviewer had been told a capacitor was replaced, and we found no new capacitor in the unit.

Symptoms that mean your air conditioner needs repair

Six symptoms account for most of the calls we take in a St. Louis summer. Each one points to a short list of parts.

• Warm air from the vents. Usually a failed capacitor, a stopped outdoor fan, a dirty condenser coil or low refrigerant.
• Water around the indoor unit. A clogged condensate drain or a frozen coil that is thawing.
• Short cycling. The system turns on and off every few minutes, often from a dirty filter, a failing contactor or an oversized unit.
• Grinding or screeching. A blower or condenser fan motor bearing on its way out. Shut it off.
• Ice on the refrigerant lines. Weak airflow or low charge.
• One room hotter than the rest. Airflow or ductwork, which a duct repair may solve better than any AC part.

Why St. Louis summers break air conditioners

St. Louis sits in ASHRAE Climate Zone 4A, and the National Weather Service logged 49 days at or above 90°F here in 2025, with 1,904 cooling degree days against a 1,713 normal. That is a long stretch of hard run time, and worn parts tend to quit on the hottest afternoon of the year.

Humidity adds a second load. Your AC removes moisture as well as heat, so the condensate drain works constantly, and algae can block it by midsummer. Cottonwood fluff in late spring packs into outdoor coils. Older north county homes add their own trouble, with undersized returns and long duct runs that starve the indoor coil of air.

How we inspect an AC that will not cool

The inspection follows the system from the thermostat to the outdoor unit, so nothing gets replaced on a guess.

1. Confirm the thermostat is calling for cooling and has power.
2. Check the filter and the airflow across the indoor coil.
3. Test the capacitor and contactor at the condenser.
4. Check the fan motors and listen to the compressor.
5. Measure temperatures and refrigerant pressures to look for a leak.
6. Clear the condensate drain and confirm the safety switch works.

Then we explain what we found in plain language. One Google reviewer put it this way: "Great at explaining things and giving you options."

Repair options and their trade-offs

Most AC repairs fall into three groups, and the right call depends on the system's age and condition.

We would rather repair your system than pressure you into a new one. When replacement really is the better buy, we say so and show you why.

What happens during the repair visit

A repair visit moves in a set order. We confirm the symptom, run the inspection, and give you a clear, upfront quote before any work starts. If you approve it, we make the repair, then run the system and check that everything else is working properly.

Many electrical repairs are finished during the first visit, though parts availability decides that. Before we leave, you will know what failed and what to watch for. A Google reviewer whose AC quit over a weekend said it was back running within 20 minutes of arrival; a larger repair takes longer, and we will tell you up front.

What an AC repair covers

An AC repair covers the failed part, the cause behind it and a check of the system around it. A capacitor that burned out from a clogged coil will burn out again, so the visit looks upstream. Typical scope:

• Diagnosis of the failed part with a meter, gauges and a visual check, before any quote
• Electrical repairs at the condenser, including capacitors, contactors, relays and wiring
• Condenser fan and indoor blower motor replacement when the motor is the fault
• Condensate drain clearing and a test of the drain safety switch
• Condenser coil cleaning when debris is what drove the pressure up
• A run test afterward and a check of what else is working

A compressor or coil replacement is quoted separately, next to the price of a new system.

Permits and licensing for AC repair

Whether a repair needs a permit depends on the job and the address. St. Louis County requires a permit to install, alter, repair or replace heating and cooling systems, and treats filter changes and refrigerant recharges as non-permit work. Inside the City of St. Louis, Ordinance 70800 requires replacement units to be installed by a mechanical contractor licensed in the City, with a permit. Missouri has no statewide HVAC license, and municipal rules vary. Ask your local building office, and have the quote say who handles any permit.

What does AC repair cost in St. Louis?

AC repair cost depends on the part, the labor time and whether refrigerant is involved. Angi reports St. Louis HVAC labor at about $75-$150 per hour in 2026, which is a market figure and not our quote. Ask whether a quote is hourly or flat, and get the number before work starts. Our AC repair cost guide walks through what moves the price.

For scale, This Old House's March 2026 guide lists national ranges of $150-$400 for a capacitor, $300-$800 for a fan motor, $80-$250 for drain line cleaning and $200-$1,500 or more for a refrigerant leak repair, with compressors at $1,000-$3,000 or more. Most repairs land between $150 and $650 in that guide. These are third-party market figures, not Kenan Corporation prices. A full HVAC replacement in St. Louis runs $4,755-$11,888, Angi's 2026 data says, so a compressor quote on an old unit belongs next to that number.

Four things change the price most:

• The part itself, from an inexpensive capacitor to a compressor
• Whether the unit needs a refrigerant leak search
• Access, such as an attic air handler or a tight side yard
• The system's refrigerant type, since older R-22 supply is limited

Why Kenan Corporation for AC repair

Our proof sits in what customers wrote on Google, where we hold a 4.6★ rating from 29 reviews as of October 2026.

• Diagnosis before parts. A Google reviewer was told a new furnace was needed, and we traced the problem to a capacitor. The same habit applies to every AC call.
• Open 24 hours. Call any time. We offer same-day service when the schedule allows.
• Repair-first since 2010. Kenan Corporation was founded to bring honesty back to a trade that had started leaning on hard-sell commission goals.

Ask us, or anyone you hire, for the license number that applies to your address. Missouri has no statewide HVAC license, so the City of St. Louis and St. Louis County license contractors separately.

Where we repair air conditioners

Drive times are from our base near Spanish Lake in normal traffic and are not arrival promises.

• Spanish Lake, about 5 minutes: cottonwood fluff from the Columbia Bottom river lowlands clogs condenser coils each spring, and apartment condensers share drain lines.
• Ferguson, about 20 minutes: the median home dates to about 1957, and Old Ferguson West's Victorians and Craftsmans have duct runs that can starve a coil of air.
• Florissant, about 20 minutes: roughly 18,000 houses went up between 1947 and 1980, so many condensers are on a second or third compressor.
• Jennings, about 20 minutes: the median home was built in 1955, and 55 percent of occupied units are rented, so the owner often wants the cause named first.
• Hazelwood, about 25 minutes: housing peaked in the 1960s, and rentals near the business parks mean condensers on several tenants' bills.
• Bridgeton, about 30 minutes: nearly 8,000 single-family homes came from the 1960s peak, which puts original-era capacitors and contactors at the end of their life.
• Maryland Heights, about 35 minutes: about 36 percent of units sit in buildings of five or more, where rows of condensers fail the same few ways.
• Lemay, about 45 minutes: 83 percent of homes predate 1970, so coils sit on ductwork first built for heat.
• Oakville, about 65 minutes: 1970s homes carry a heavy cooling load near the Meramec and Mississippi, and a blocked drain shows up in July.

Call first if you are at the far end of that range.

How do you keep the AC from failing again?

Prevention is mostly airflow and timing. Change the filter on schedule, keep two feet clear around the condenser, and rinse cottonwood off the coil gently in late spring. Book AC maintenance before the first heat wave, when small problems are still small. If your system already keeps breaking, price the repair against replacement before the next hot spell.