Before You Call: Check These First
- • Thermostat set to COOL and below current room temperature
- • Air filter — replace if it's been more than 30 days
- • Outdoor unit — clear debris from around the unit
- • All supply vents are open and unblocked
- • Breaker hasn't tripped (check your panel)
If all of those are fine and your AC still isn't cooling — call us. The cause is internal and requires a licensed technician.
6 Reasons Your AC Is Running But Not Cooling in Houston
Low Refrigerant (Most Common)
Refrigerant doesn't get "used up" — if levels are low, there's a leak. Common in Houston due to humidity-accelerated coil corrosion. Symptoms: AC runs constantly, warm air from vents, ice on the refrigerant line.
Fix: Leak detection, repair, and proper recharge.
Dirty Condenser Coils
The outdoor unit transfers heat from your home to the outside air. When the coils are caked with dirt, grass, and debris, heat can't escape — your house stays warm no matter how long the AC runs.
Fix: Professional coil cleaning restores full cooling capacity.
Frozen Evaporator Coil
Ice on your indoor coil blocks airflow and heat exchange. Caused by low refrigerant, dirty filters, or restricted airflow. If you see ice on your AC lines, shut the system off and call us.
Fix: System defrost, root cause diagnosis, and repair.
Failed Capacitor
The capacitor starts your compressor and fan motors. When it fails — extremely common in Houston's heat — your AC may hum, run without cooling, or not start at all.
Fix: Capacitor replacement, typically $150-300, same-day.
Compressor Failure
The compressor is the heart of your AC. When it fails, the system blows air but produces no cooling at all. Compressor failures are costly but diagnosable in one visit.
Fix: Compressor replacement or system evaluation for full replacement.
Dirty or Clogged Air Filter
A severely clogged filter starves your system of airflow, causing the evaporator coil to freeze and your home to stop cooling. Check and replace your filter monthly in Houston.
Fix: Filter replacement — something you can do yourself today.
AC Still Not Cooling? We'll Fix It Today
Same-day diagnostics and repair throughout Houston TX. Licensed, insured, upfront pricing.
Houston-Specific AC Cooling Problems
Houston's climate is exceptionally hard on air conditioning systems. With heat indices regularly exceeding 110°F from May through September, your AC runs nearly continuously — accelerating wear on every component. The high humidity (75-90% during summer) speeds up coil corrosion, causing refrigerant leaks to develop faster than in drier climates. Coastal air quality also introduces salt-laden moisture that corrodes electrical connections and contactor points. These Houston-specific factors mean an AC system that worked fine last summer may fail suddenly this summer — with no warning signs. When it does, AOT Mechanical is ready with same-day service throughout Greater Houston.
Frequently Asked Questions
What Houston Homeowners Say
"AC was running all day but house stayed at 85°. AOT came same day, found a refrigerant leak, and fixed it in 2 hours. House was cool by dinner. Outstanding!"
James P.
Houston, TX
"AC not cooling — called 3 companies, AOT was the first to answer and show up same day. Turned out to be a failed capacitor, $200 fix. Fast and honest."
Maria G.
Katy, TX
"Frozen evaporator coil from a refrigerant leak. AOT diagnosed it immediately, explained exactly what happened, and fixed it same afternoon. Very professional."
David L.
Sugar Land, TX
