AC Repair in O'Fallon, MO
Air conditioners here run from May through September. If yours quits, tell us what it's doing and a licensed contractor who covers St. Charles County will get in touch.
Tell us about the job
It takes about a minute.
Five months of summer heat, plus what the storms leave behind
Your AC runs from May through September here, with summer afternoons averaging 87°F. That's a long stretch of steady, hard work for the compressor and the fan motor, and it shows up as reduced cooling or a system that runs but can't keep up on the hottest days.
St. Charles County has also seen 39 hail events and 84 damaging wind events over the past ten years, with hail up to 4 inches. Hail that size bends the fins on your outdoor unit and can crack the fan blades, and high winds can knock the unit out of level or loosen the electrical connections inside it. If your air conditioner started struggling right after a storm, that's usually not a coincidence.
- 5 months
- May through September, your air conditioner is on duty
- 87°F
- the average summer afternoon it cools against
- 39 hail events
- in ten years, and hail bends the fins on outdoor coils
- 84 wind events
- in ten years, and wind drives debris into outdoor units
NOAA nClimDiv, 1991–2020 normals
A new air conditioner would save little on running costs in St. Charles County, so the repair decision comes down to the unit's condition.
Estimates for a typical St. Charles County home, compared with an older unit built to the previous federal minimum, from EIA household energy data, Missouri fuel prices and NOAA climate normals. Your home will differ.
Repair makes sense when a part like a capacitor or contactor has failed.
Replacement makes sense when the compressor has failed or the system uses R-22 refrigerant, which is no longer made.
- Why is my AC not blowing cold air?
- Most of the time the filter is clogged and starving the system of airflow, or the refrigerant is low from a leak somewhere in the line. A dirty outdoor coil can cause the same problem, since it stops the unit from shedding heat the way it needs to. Check the filter first since that's the one thing you can rule out yourself. If it's clean and the air is still warm, the system needs a contractor to check refrigerant levels and look for a leak.
- Why is my AC leaking water?
- The condensate drain line is probably clogged, which backs water up until it overflows the pan. This happens more in summer here since the system runs for long stretches from May through September and algae or dirt builds up in the line over time. A frozen coil that's now thawing can also flood the pan faster than it can drain. Either way, the system should be shut off until a contractor clears the line and checks the coil.
- Why won't my AC turn on?
- Start with the thermostat batteries and the breaker before assuming the worst. A tripped breaker or a dead thermostat display will stop the whole system cold and both are easy to check yourself. If power is fine at the breaker and the thermostat is set correctly, the problem is likely inside the unit, in the capacitor or the contactor, and that needs a contractor to diagnose. With 84 damaging wind events recorded here over the past ten years, it's also worth checking the outdoor disconnect box near the condenser, since storm debris or a loose connection there can keep the outdoor unit from starting even when the indoor part has power.