AC Replacement in St. Louis, MO

A broken air conditioner does not automatically mean a new one. AC replacement in St. Louis makes sense when the compressor or coil has failed on an old system, when repairs keep stacking up, or when the refrigerant is R-22. In many other cases a capacitor, motor or drain fix buys years.

Is it time to replace your air conditioner or repair it?

Repair when the failed part is small and the compressor is sound. Replace when the failed part is large and the system is near the end of its life.

Contractor sources put air conditioner life at about 15 to 20 years with routine maintenance. Within that window, weigh these four points:

• The failed part. Electrical parts and fan motors are modest repairs. Compressors and coils are not.
• The refrigerant. R-22 is still serviceable, but EPA ended its production and import in 2020, so a leak on an R-22 system gets expensive.
• The repair history. A third repair in two summers points to wear everywhere.
• The house. Rooms that never cool well may be a duct or sizing problem that a new unit would not fix.

How do we decide when an old AC is not worth fixing?

We diagnose first, then price both paths side by side. A Google reviewer who goes by Margaret S. had been told a capacitor was replaced, and we found no new capacitor, only a failing fan motor. That is why a quote should come after the testing, never before it.

When replacement really is the better buy, the signs are plain: a failed compressor, a leaking coil on an R-22 unit, or a system that no longer reaches temperature. Ms. O., another reviewer, had an old, rusty, leaking AC and needed a new system installed. We say that when it is true and show the reasoning.

What did Angi report for AC replacement costs?

Angi's 2026 figures for a full HVAC replacement in St. Louis range from $4,755 to $11,888, with an average of $7,133. The same data puts labor at $75 to $150 per hour, or $1,500 to $5,000 of a full replacement. Those numbers describe furnace and AC together, so an air-conditioner-only job usually costs less.

These are market figures, not a Kenan price. What moves your number:

• Tonnage and efficiency rating
• Whether the indoor coil, ducts or thermostat change too
• Electrical work and access, such as an attic air handler
• Permit costs and old-unit disposal

DOE sets 13.4 SEER2 (14 SEER) as the 2023 minimum for a split AC under 45,000 Btu/h in its North region, which includes Missouri, so every quote you receive should meet it. Fixr's January 2026 national guide puts a 3-ton central AC near $6,000 installed, a useful cross-check on the AC-only share of Angi's combined range.

What replacement options do you have?

There are four sensible routes, and the cheapest at first is not always the cheapest over ten summers.

Federal 25C does not apply to equipment placed in service after December 31, 2025, per the IRS. Ameren's 2026 chart pays $2,000 per system on qualifying air-source heat pumps, through a participating contractor. Use Ameren's Find a Contractor tool before signing.

What happens during the replacement?

The visit follows a set order once you approve the quote.

1. Confirm the load calculation still fits the house.
2. Recover the old refrigerant and disconnect the unit.
3. Remove the old condenser and, if the quote includes it, the coil.
4. Set the new equipment, reconnect the line set and drain, and wire the disconnect.
5. Evacuate the lines, charge the system and test airflow and temperature drop.
6. Show you the thermostat and filter, and explain what was replaced.

What the replacement scope covers

An AC replacement covers the equipment, the connections and the paperwork around it, and it starts from the repair-or-replace findings. The old unit's age, refrigerant and failed part are written down first, so the quote answers the question you actually asked. Then the scope is itemized, and anything left out of a line should be marked excluded. A usual scope runs:

• A check of the old unit's size against the house, or a fresh load calculation
• A new condenser and, where the quote says so, a matched indoor coil or air handler
• Refrigerant recovery from the old system, then evacuation and a charge on the new one
• Pad, line set, disconnect and drain connections as the quote lists them
• The permit plan, with the final inspection record handed to you
• A start-up test of temperature drop and airflow, plus a thermostat walkthrough

Disposal of the old unit and any duct or electrical changes belong on their own lines, so you can see what each one adds.

Why Kenan Corporation for an AC replacement decision

We hold a repair-first stance because the business was built on it.

• Founding reason. Kenan Bruce Martz started Kenan Corporation in 2010 after 20-plus years at St. Louis area HVAC companies, because he disliked the commission goals and hard-sell pitches he saw.
• Diagnosis before a new-unit quote. Wendy R., a Google reviewer, was told by another company to buy a new furnace. Kenan found a capacitor and fixed it.
• Options in plain language. The 4.6★ rating on Google, from 29 reviews as of October 2026, includes comments that we explain things and give options.
• Open all hours. If the unit dies at 2 am, a call gets answered, and a visit the same day happens when the schedule allows.

We serve Affton, Mehlville, Florissant and Ballwin. Affton is about 50 minutes from our base near Spanish Lake in normal traffic, Florissant about 20. See Affton, Mehlville and Florissant.

What do the permit and license rules say?

A replacement is permit work, and the installing contractor pulls the permit. St. Louis County requires a mechanical permit to replace heating and cooling systems and licenses mechanical contractors through its Department of Transportation and Public Works. The City of St. Louis requires a City-licensed mechanical contractor for replacement units and charges a $25 application fee. Ballwin wants an active County license plus a city contractor license.

Ask any contractor, including us, for the license number that applies to your address, and get the permit in the quote. Refrigerant work also calls for EPA Section 608 certification, which you can ask to see.

Where we replace air conditioners

Times are normal-traffic drives from our base near Spanish Lake, and none is an arrival promise.

• Florissant, about 20 minutes: the median home was built in 1963 and the 1960s were the biggest building decade, so many systems here are on their second or third unit.
• Webster Groves, about 40 minutes: the city issues permits only to contractors registered with it, with a plan-review fee and a per-inspection fee, so ask which of those sit in your quote.
• Shrewsbury, about 45 minutes: the 1980s built the most homes at 21 percent, and the city's permit forms disagree on mechanical work, so confirm city or county first.
• St. Peters, about 45 minutes: the city grew from about 15,700 people in 1980 to 45,779 in 1990, and its code wants contractors examined and licensed by St. Charles County.
• Affton, about 50 minutes: median year built 1958, and 81 percent of homes heat with gas, so a replacement is usually a condenser and coil matched to an existing gas furnace.
• Kirkwood, about 50 minutes: a municipal electric utility serves about two-thirds of the city, so check which utility serves your address before counting on an Ameren rebate.
• O'Fallon, about 50 minutes: Ameren and Cuivre River Electric Cooperative both serve customers inside the city, which decides whether the 2026 heat pump rebate can apply.
• Mehlville, about 55 minutes: this is unincorporated, but some Mehlville-addressed parcels sit inside incorporated cities, so confirm the permit office before signing.
• Ballwin, about 55 minutes: permits go through the city's online portal, and inspections are scheduled by phone with the city.
• Oakville, about 65 minutes: St. Louis County allows a no-plan permit for like-for-like replacements, so ask whether yours qualifies.

Call before booking if you are in one of the farther towns.