Tell us about the job
Takes about a minute. No obligation.
The compressor in a central AC unit starts and stops every cooling day, and each cycle loads the contacts, the capacitor, and the refrigerant circuit. Homes in Mississippi County, MO run cooling about five months a year, from May through September. Contractors diagnosing a failed system here check the contactor for pitting and the capacitor for swelling before they pull anything else, because those are the parts that take the hit from repeated starting across a long run. A compressor that was marginal at install has had little idle time to stay marginal.
Ductwork in a house built for an earlier era of cooling tends to carry the evidence of every system that has run through it since. Joints seal and reseal. Insulation thins. A contractor pulling a failing component out of the air handler is also looking at what the surrounding ductwork has done to airflow and back-pressure over that span, because that is often what accelerated the failure. Half the homes in Mississippi County, Missouri were built in 1973 or earlier (2020-2024 ACS 5-year). A system that has been working against compromised ducts wears differently than one that has not, and the opened unit shows it. Parts availability is its own question once a contractor knows exactly what model is in there.
The Parts of a Central AC a Contractor Checks During a Repair
The outdoor condenser unit sits on a concrete pad outside the house and holds the compressor and condenser coil. These are the parts a contractor goes to first when the system is running but not cooling, making noise, or tripping a breaker. The indoor evaporator coil, tucked inside the air handler or furnace cabinet, is the other common source of trouble, particularly when airflow drops or ice appears on the lines.
The air handler or furnace cabinet that houses the evaporator coil also contains the blower motor, which moves air through the system. The refrigerant lines running between the indoor and outdoor units and the copper connections at each end are inspected whenever the system loses its charge or cycles incorrectly. The thermostat, mounted on an interior wall, rounds out what a contractor checks when diagnosing a complaint.
The drawing shows the general layout of a central AC system, and a licensed contractor determines which parts apply to the specific setup in your house.
Get matched in Mississippi CountyMississippi County, Missouri, by the numbers
99 severe weather events were recorded in Mississippi County, Missouri between 2015 and 2024.
NOAA National Centers for Environmental Information, Storm Events Database, bulk CSV export, events 2015-01-01 through 2024-12-31.Half the homes in Mississippi County, Missouri were built in 1973 or earlier (2020-2024 ACS 5-year).
U.S. Census Bureau, 2020-2024 American Community Survey 5-Year EstimatesMississippi County, Missouri holds 5,272 housing units (2020-2024 ACS 5-year).
U.S. Census Bureau, 2020-2024 American Community Survey 5-Year EstimatesOwners occupy 62.9% of the occupied homes in Mississippi County, Missouri (2020-2024 ACS 5-year).
U.S. Census Bureau, 2020-2024 American Community Survey 5-Year EstimatesCodes & Standards Covering Central AC Repair in Mississippi County, Missouri8 sourced rules and standards
What happens when a contractor comes out to repair your HVAC
Split-system central air conditioners rated below 45,000 Btu/h manufactured on or after January 1, 2023 must meet a federal minimum of 13.4 SEER2.
Split-system central air conditioners rated at or above 45,000 Btu/h manufactured on or after January 1, 2023 must meet a federal minimum of 13.4 SEER2.
Split-system central air conditioners manufactured between January 1, 2015 and December 31, 2022 had to meet 13 SEER, the metric that preceded SEER2.
Single-package central air conditioners manufactured on or after January 1, 2023 must meet a federal minimum of 13.4 SEER2.
Space-constrained central air conditioners manufactured on or after January 1, 2023 must meet a federal minimum of 11.7 SEER2.
Federal efficiency standards for split-system central air conditioners and heat pumps are set on each certified combination of outdoor unit and indoor coil rather than on the outdoor unit alone.
Residential and light commercial air conditioning and heat pump systems assembled in the field, including mini-splits and unitary systems, may not be installed on or after January 1, 2025 using a refrigerant with a global warming potential above 700.
A field-assembled system whose specified components were all manufactured or imported before January 1, 2025 carries no installation compliance date under the refrigerant restrictions and may still be installed.
Severe Weather Events in Mississippi County
Hard weather puts real hours on AC equipment. Compressors, capacitors, and refrigerant lines wear faster when the system runs through sustained heat, power fluctuations, and storm stress, and that wear is what brings a repair call.
99 severe weather events, 2015–2024. Source: NOAA National Centers for Environmental Information, Storm Events Database.