Troubleshooting an AC that is not cooling in Memphis, TN means working through the usual suspects: restricted airflow from a dirty filter, a failed contactor or capacitor, a frozen evaporator coil, a refrigerant leak leaving the charge low, a dirty condenser coil and drain trouble that trips the system off. Use Call Now to say what the system is doing and you will be connected with an independent HVAC contractor serving 59 ZIP codes around Memphis.
Why an air conditioner runs but does not cool
| Symptom | Likely cause | What the technician checks |
|---|---|---|
| Fan runs, outdoor unit silent | Failed capacitor, contactor or tripped safety | Capacitor microfarads, contactor contacts, breaker and float switch |
| Ice on the lines or the coil | Restricted airflow or low charge | Airflow, coil, charge and thermostat settings |
| Air is cool but weak | Dirty filter, closed registers, failing blower motor or blocked return | Filter, blower amperage and static pressure |
| Water near the air handler | Clogged condensate drain | Drain line, pan and float switch |
| Air is only slightly cool | Low refrigerant or dirty condenser coil | Pressures, superheat, subcooling and coil condition |
Low refrigerant means a leak
Low refrigerant always points to a leak because refrigerant is not consumed. Adding more without finding the leak is a temporary fix. The technician uses an electronic detector, nitrogen pressure test or dye to locate it, repairs or replaces the part, and recharges to the manufacturer's specification.
What you can check safely before you call
- Outdoor unit free of leaves, grass and debris
- Breaker on, and the outdoor disconnect pushed in. Do not open electrical panels
- Filter replaced or cleaned if it is dirty
- Supply and return registers open and not blocked by furniture
- Thermostat set to cool, lower than the room temperature, with fresh batteries if it uses them
Electrical parts that fail in the heat
Heat and age wear down the run capacitor, which supports the compressor and fan motors at startup and while running; a weak capacitor shows up as hard starts, humming or a unit that will not start. The contactor is a switch that sends power to the outdoor unit, and its contacts pit and burn over the years. They are minor parts compared with the compressor they protect, which is the reason technicians check them first when it is hot.
Coils, airflow and why they matter
In the evaporator coil, heat passes from the indoor air to the refrigerant, and at the condenser coil it is released outdoors. A dirty coil, or a filter or ducts that restrict airflow, stops the system from moving that heat. As a common rule of thumb, a healthy system shows a temperature drop of about 15 to 20 degrees across the indoor coil, while a much smaller drop suggests airflow or charge problems.
How an AC not cooling visit works, step by step
A diagnostic visit should follow a repeatable order so the technician finds the cause, not just the symptom. Knowing the order helps you tell a thorough visit from a part swap.
- Interview: what you noticed, when it started, how the system sounds and what you have already tried.
- Visual check: thermostat settings, filter, supply and return registers, the air handler, the condensate line and the outdoor unit.
- Electrical tests: breaker and disconnect, capacitor microfarad rating, contactor contacts, motor amperage and control voltage.
- Airflow and temperature: the temperature drop across the evaporator coil and, where needed, static pressure in the ductwork.
- Refrigerant checks: pressures, superheat and subcooling, and a leak search if the charge is low.
- A written finding: the cause, the repair options and what each one would fix, before any part is replaced.
Questions to ask before approving a repair
- Will you give me the findings and the scope in writing before work starts?
- What are my options: repair now, repair and monitor, or replace?
- What does the repair warranty cover and for how long?
- How old is the system and which refrigerant does it use?
- What failed, how did you confirm it and can you show me the part or the reading?
Safety and rules to know
Three hazards share one machine in an air conditioner: high-voltage electricity, pressurized refrigerant and moving parts. Opening electrical panels, bridging contactors and adding refrigerant are not jobs for homeowners, and capacitors can keep a charge after the power is off.
In the United States, anyone who buys or handles refrigerant must be certified under EPA Section 608, and refrigerant must be recovered and not vented. Ask the technician for their certification and check the contractor's licence with Tennessee Board for Licensing Contractors (HVAC classifications).
What makes AC not cooling different in Memphis
Hot, humid Mid-South summers with heat indexes often above 100 degrees; winters can bring ice storms. Humidity drives condensate drain clogs, sweating ducts, and mold in air handlers.
Memphis Light, Gas and Water (MLGW) is the local utility. Older homes in Midtown, Cooper-Young, Binghampton, and Whitehaven; newer homes in Cordova, Collierville, Germantown, and Bartlett. The diagnosis and the equipment recommendation for your address can both be shaped by these local conditions, so ask the technician how.
AC not cooling across Memphis and nearby cities
59 ZIP codes in Memphis, Tennessee fall within the area of Air Conditioning Repair Memphis: 37501, 37544, 38101, 38103, 38104, 38105, 38106, 38107, 38108, 38109. Requests may also go to providers who serve Ellendale, Germantown, Cordova and Collierville. Coverage depends on the address, so state your ZIP code on the call.
An independent HVAC contractor is one call away: use Call Now at the top of any page and describe the symptoms and the age of the system. The contractor confirms your address, then examines the system in person to diagnose it.
Related help in Memphis
If this is not quite your situation, these pages cover the neighboring questions: AC Not Cooling? 12 Causes and Fixes; How to Lower Cooling Bills; Heat Pump Defrost and Emergency Heat; AC Replacement. The service area list shows every nearby city and ZIP code covered.
AC Not Cooling in Memphis: common questions
What if my AC is too old to repair?
A technician can give the age, the refrigerant type and an idea of repair versus replacement cost. With a major failure on a system older than roughly 12 to 15 years, replacement is often worth weighing.
How do I know if the capacitor is bad?
Signs include a humming outdoor unit that does not start, a fan that needs a push, or a unit that clicks. Only a technician should test or replace it because capacitors can hold a charge.
Why is my AC running but not cooling?
Common causes are a dirty filter, a failed capacitor or contactor, a frozen coil, low refrigerant and a dirty condenser coil. A diagnostic visit tests each in order and tells you which applies.
Can low refrigerant be fixed by adding more?
Adding refrigerant without repairing the leak is a stopgap. The leak should be found and repaired, and the system recharged to specification.
Should I keep running the AC if it is not cooling?
No. If there is ice on the unit or lines, turn the cooling off and set the fan to on so the ice melts. Running a frozen or failing system can damage the compressor.
How long does a diagnostic visit take?
Often under an hour, depending on access and the complexity. The provider will explain what they find and what is needed.