An outside unit that hums while the fan stays still is the call we get most in July in Florissant, MO, and the cause is usually a failed run capacitor. That inexpensive component starts the compressor and fan, fades for years without complaint, and then quits under peak load. It is far from the only suspect, though. Contactors pit and stop passing clean power, condenser fan bearings dry out, small refrigerant leaks drain away cooling capacity, and evaporator coils ice over when a clogged filter strangles airflow.
Warm air from the vents can mean a failed capacitor, a refrigerant leak, a frozen coil, or a duct problem, and each one carries a very different price to fix. That is why Florissant HVAC tests before touching anything. We meter capacitors against their microfarad rating, compare compressor and fan amp draws to the data plate, judge the refrigerant charge by superheat and subcooling instead of pressure alone, and inspect the coil, blower wheel, and filter whenever there is ice. Topping off refrigerant without locating the leak only buys cold air until the charge leaks out again.
Central air, heat pumps running in cooling mode, and ductless mini splits from every major brand are all in our wheelhouse. Because our trucks carry capacitors, contactors, fan motors, hard-start kits, and condensate pumps, most AC repairs are completed the same visit. If the compressor has failed on an older system, we tell you so directly and show you the numbers on repairing versus replacing. Call (557) 256-7420 and we will get cold air flowing in your Florissant home again.
Heating trouble instead? See Furnace Repair in Florissant.
How Much Does AC Repair Cost in Florissant?
Most air conditioner repairs in Florissant land between $150 and $650. Where you fall in that range depends almost entirely on which component failed. You'll get an upfront quote from Florissant HVAC before we touch a single part.
| Repair | Typical cost | What it usually means |
|---|---|---|
| Capacitor replacementMost common repair, usually same visit | $150–$400 | The most common AC failure; outdoor unit hums but won't start |
| Contactor replacementWorn relay that stops the condenser from starting | $150–$350 | Worn relay that stops the condenser from starting |
| Condenser fan motorOutdoor fan stops, compressor trips on high heat | $300–$700 | Outdoor fan stops, compressor trips on high heat |
| Refrigerant leak repair + rechargeDepends on leak location and refrigerant type | $300–$1,500 | Varies with where the leak is and how much charge is lost |
| Evaporator coil replacementCorroded or leaking indoor coil | $1,000–$2,500 | Major repair; worth weighing against replacement on older systems |
| Compressor replacementLargest single repair; often weighed against a new system | $1,500–$3,000 | On systems past 10–12 years, replacement usually makes more sense |
Typical ranges for common repairs. Your exact price is quoted after diagnosis.
What Moves the Cost Up or Down
- How old the unit is and how easy its parts are to source
- Refrigerant type, because R-22 recharges are much more expensive
- Timing, such as same-day or after-hours service versus a scheduled visit
- How hard the equipment is to reach, such as attics, crawlspaces, or rooftops
If a repair would cost more than a third of a new system, or your AC is past 12 to 15 years old, we'll show you both numbers side by side so you can decide. Call (557) 256-7420 for a quote.
Warning Signs for AC Repair
Recognizing the warning signs early can save you time, money, and prevent significant damage to your property. Here are the most common indicators that it's time to call a professional:
- Rising electric costs paired with a sticky, uncomfortable house
- Room-temperature air from the registers even though the AC is running
- A burning smell or repeated breaker trips when the AC starts
- The system short-cycling every few minutes without cooling the house
- The outdoor unit humming or clicking but the fan not spinning
- Hissing or bubbling sounds that suggest a refrigerant leak
- Frost or ice forming on the copper lines or the indoor coil
- Water dripping from the indoor unit or showing up on the ceiling below
Early Action Saves Money
A failing capacitor, clogged condensate drain, or dirty flame sensor rarely fixes itself and usually gets more expensive to address the longer it runs. At the first hint of a problem, reach out to Florissant HVAC at (557) 256-7420 for a fast inspection.
AC Repair Issues? We Can Help.
Call Florissant HVAC for fast, reliable service.
Call (557) 256-7420 TodayFrequently Asked Questions About AC Repair
Why Professional AC Repair Matters
Start with the refrigerant. It lives in a sealed, pressurized loop, venting it is prohibited under federal rules, and correct service requires gauges, a vacuum pump, and a recovery machine rather than a store-bought recharge kit. Add capacitors that hold a dangerous charge with the power off and a condensing unit fed by 240 volts, and the risks add up quickly. Then there are the diagnostic traps: an iced coil often points to poor airflow rather than low charge, and topping off a system with an unrepaired leak lets moisture and acid slowly damage the compressor while your money leaks out with the refrigerant.
What you get from a pro is a repair that holds. Our experienced technicians find leaks with dye and electronic detectors, base every charge decision on superheat and subcooling, test electrical parts with a meter before condemning them, and measure static pressure and inspect the blower and filter whenever airflow is in question. Parts-cannon fixes tend to bring you back in a few weeks. Ours are built to last through the heat. And if the numbers say replacement is the better call, we show you those numbers honestly, without pressure.
What to Expect From Our AC Repair
Our systematic workflow delivers thorough, lasting results on every job. Here's a look at each step our Florissant HVAC team takes:
System Diagnosis
Before we replace anything, we meter the electrical components, read the refrigerant charge with superheat and subcooling, and look over the coil, filter, and condensate line for the actual cause.
Clear Explanation & Price
Nothing happens without your approval. We explain what broke and why, quote a firm price, and, if the compressor or coil has failed, walk you through repair versus replacement honestly.
On-the-Spot Fix
Most AC fixes happen right away. We carry capacitors, contactors, fan motors, and other high-failure parts, so there is rarely a wait on a parts order.
Performance Verification
We confirm a healthy temperature split across the coil, verify amp draws and charge, clear the condensate line, and watch a full cooling cycle before we leave.
Want a Professional Opinion?
We provide honest advice and upfront pricing on all AC repair work.
Get Help: (557) 256-7420How to Prevent AC Repair Problems
A few simple habits now, like regular filter changes and seasonal tune-ups, can add years to your system's life. Start with these practical measures our team relies on:
- Avoid shutting registers in unused rooms, which raises static pressure and stresses the blower
- Schedule a spring tune-up so weak parts are caught before summer arrives
- Rinse the outdoor condenser coil each spring and keep vegetation two feet back
- Swap filters monthly while the AC is running hard to keep the evaporator coil from icing
- Start each cooling season by flushing the condensate line so algae cannot block it
- A new buzz or click at startup often means a weak capacitor, so call before it fails
- Shade is fine, but do not box in the outdoor unit with fences or covers
Should You DIY or Call a Pro?
While some minor tasks like changing filters or checking a thermostat can be handled by homeowners, most HVAC work involves refrigerant, gas combustion, and high-voltage electricity, jobs that call for professional expertise. Here's a comparison:
| Factor | DIY Attempt | Professional Service |
|---|---|---|
| Refrigerant | Top-offs without finding the leak | Leak found and fixed, then charge weighed in |
| Electrical Safety | Risk of shock from 240V and stored charge | Circuits tested dead before any work |
| Frozen Coils | Thawed and refrozen on repeat | Root cause found: airflow or charge |
| Diagnosis | Guesswork on faults that look the same | Meters, gauges, and temperature clamps |
| Parts | Parts that are almost the right rating | Specs matched to the equipment data plate |
| Result | Short-lived relief | Repair verified under real load |
Talk to a AC Repair Expert
Get your comfort back before a small fault becomes a full breakdown. Florissant HVAC is ready to respond fast.
Call (557) 256-7420 NowAC Repair Across the Florissant Area
We serve Florissant and its neighboring communities for AC repair, from quick same-day repairs to planned installs.