top of page
ac troubleshooting




Looking to fix an AC issue on your own? Be sure to look over the provided air conditioning troubleshooting tips. 

No Air Blowing in the House, AC Not Running Outside

  • Verify that your thermostat is set to cool, and the set point is below the room temperature.

  • Check to confirm that the furnace or air handler is plugged in.

  • Check the circuit breaker. This is typically marked FURNACE, Heater or AH on the breaker panel cover (check power by plugging a hair dryer into the same outlet).

  • Replace the thermostat’s batteries.

No Air Blowing in the House, AC Is Running Outside


  • Check your air filter. A dirty air filter may indicate you have a frozen evaporator.

  • If the filter is clean and the furnace can be heard running indoors, check for closed registers. Insufficient air flow will freeze a coil.

  • Be on the lookout for signs of ice at the copper lines outdoors and indoors.

  • Turn the system to OFF and put the fan in the ON position for 1.5 to 2 hours to defrost the coil. Turn it back and hopefully you will have air while you await our arrival, at which point we can test the rest of the system.

  • Be prepared for water resulting from melting ice.

Air is blowing in house, AC is not running outside


  • ​Check your fuses and/or circuit breaker. This is typically marked “AC.”

  • You can have fuses checked at a local hardware store. Wait for a technician if you do not know where to find your fuses.

  • Take safety precautions around electricity and turn circuit breakers off before testing fuses.

  • Watch for water leaks around the furnace.

  • Check your air filter. A dirty filter may cause the evaporator to freeze (see above concerning freeze up).

  • Possibilities include a plugged condensate drain. A worst-case scenario may involve a rusted out evaporator (typically after 10 years of use).

Troubleshooting Your Residential A/C Unit

Is your home feeling warmer than it should be, despite your air conditioner being on? Don't sweat it! Many common A/C issues can be resolved with a little DIY troubleshooting. Before calling in the professionals, follow these steps to identify and potentially fix the problem.

1. No Cooling at All

Check the Thermostat Settings:

  • Ensure your thermostat is set to "Cool" and the desired temperature is lower than the current room temperature.

Replace the Air Filter:

  • A clogged air filter can restrict airflow. Replace it regularly (usually every 1-3 months) to maintain proper air circulation.

Circuit Breaker:

  • Inspect the circuit breaker for the A/C unit. If it's tripped, reset it. If it trips again, consult an electrician.

2. Poor Cooling Performance

Clean the Evaporator and Condenser Coils:

  • Over time, dirt and debris can accumulate on these coils, reducing efficiency. Clean them using a soft brush or coil cleaner.

Refrigerant Leaks:

  • Low refrigerant levels can impair cooling. If you suspect a leak, contact a professional technician for repairs.

Thermostat Calibration:

  • Make sure your thermostat is calibrated correctly. If it's not, it can cause inaccurate temperature readings.

3. Strange Noises

Blower Fan:

  • Check the blower fan for obstructions or loose components. Tighten any screws or bolts that may be causing rattling noises.


  • Some A/C units require lubrication for moving parts. Refer to your owner's manual for instructions.

4. Water Leaks

Condensate Drain Line:

  • Inspect the condensate drain line for clogs. Clear any blockages to allow proper drainage.

Unit Level:

  • Ensure your A/C unit is level. If it's not, water may not drain correctly. Use a level to adjust if needed.

5. Frequent Cycling

Air Filter:

  • A dirty or clogged air filter can cause short cycling. Replace it to improve airflow.

Thermostat Location:

  • Ensure the thermostat is not located near heat sources or in direct sunlight, as this can lead to inaccurate temperature readings.


  • Check for any obstructions around the outdoor unit that might impede airflow. Clear away debris.

Remember, safety is essential when troubleshooting your A/C unit. Always turn off the power to the unit before performing any maintenance, and if you're unsure about any steps, it's best to consult with a professional HVAC technician. Regular maintenance can help prevent many common issues, so consider scheduling annual maintenance checks to keep your A/C unit running smoothly.

If you've followed these troubleshooting steps and your A/C unit still isn't working correctly, it's time to call in the experts. They can diagnose and repair more complex issues, ensuring your home stays cool and comfortable during the hottest days of the year.


Need additional help with your air conditioning system?


We are here to help with all of your air conditioning system needs. Give us a call and one of our technicians will be right over and get things working. We look forward to speaking with you!
bottom of page