AC problem guide
AC Not Cooling? Safe Checks & Likely Causes
If the system runs but rooms stay warm, start with airflow, thermostat settings, visible ice, and whether the outdoor unit is operating.
Immediate safety notes
- Stop using the system for smoke, burning odor, visible arcing, gas odor, or a carbon-monoxide alarm.
- Do not open energized panels or refrigerant components.
Likely cause categories
ComfortGauge uses these reviewed cause categories as possibilities, not as a confirmed component diagnosis.
- airflow restriction
- refrigerant or coil issue
- outdoor power issue
Safe checks you can make
- Confirm the thermostat is set to cooling below room temperature.
- Check the filter and make sure supply and return vents are open.
- Look for visible ice and observe whether the outdoor unit is running.
What not to do
- Do not add refrigerant.
- Do not open electrical disconnects or panels.
Expected cost context
ComfortGauge does not yet have a reviewed service-specific range for this problem.
Compare written repair scopes and quotes rather than relying on an unsupported estimate.
Repair or replace context
System age, repair cost, repeat failures, comfort, and operating performance matter more together than any single symptom.
Compare repair versus replacement →Frequently asked questions
Why is my AC running but not cooling?
Several conditions can cause this, including restricted airflow, control problems, outdoor-unit faults, or coil/refrigerant issues.
Should I keep running an AC with visible ice?
No. Turn cooling off and allow the ice to thaw; persistent freezing needs professional evaluation.
What should I check first when the AC is not cooling?
Start with thermostat mode, accessible filter condition, open vents, visible ice, and whether the outdoor unit is operating.