AC Not Cooling Diagnosis
Warm supply air and long run times can have many causes, from a control setting to lost airflow or a refrigerant-system fault. Because the indoor and outdoor units work together, checking only the part that appears to be running can miss the actual problem. A diagnosis narrows the cause before a repair is recommended.
One symptom.
Several possible causes.
What causes this?
These are possibilities, not a diagnosis. Similar symptoms can come from different parts of the cooling system.
The outdoor unit may not be operating because of a control, electrical, capacitor, fan, or compressor problem.
Restricted airflow from a filter, blower, or coil can limit cooling and may cause the indoor coil to freeze.
A refrigerant leak or another sealed-system issue can reduce cooling capacity.
A thermostat setting or sensor problem may produce a cooling request that does not match conditions in the home.
What to look for
Take note of when the problem occurs and what the indoor and outdoor units are doing. Share these clues when you call.
- 01
Air from the vents stays warm even though the thermostat indicates cooling.
- 02
The system runs continuously or for unusually long periods without approaching the set point.
- 03
The indoor unit runs while the outdoor unit is silent, or ice forms on a line or coil.
Do not keep forcing a system to run if it is icing, repeatedly tripping a breaker, or leaking water near electrical equipment. Leave electrical and refrigerant work to qualified professionals.
What our technician will do
The indoor and outdoor units are evaluated together to locate the fault before repair options are discussed. The findings help determine which repair, if any, addresses the actual fault. Repair pricing is quoted after diagnosis; review the proposed work and price before approving a repair.
Confirm the cooling request, operating mode, and what the indoor and outdoor units do in response.
Check airflow, electrical and control operation, and cooling measurements as indicated by the initial findings.
Identify the likely fault, explain any further diagnostic need or repair options, and obtain approval before repairs.
After an approved fix, verify system operation and temperature response under the conditions available.
What to tell us when you call
- Is your AC blowing warm air or no air?
- Is the outdoor unit running?
- When did the problem start?
- Have you noticed unusual noises, ice, or leaking water?
These details help our technician prepare. You don’t need to diagnose the problem yourself.
Need help with your AC?
Tell us what you've noticed at home. Scheduling depends on your address and the current appointment schedule; contact us to discuss the next step.