If your air conditioner is blowing warm air, it is usually caused by a dirty air filter, incorrect thermostat settings, a tripped breaker, or a refrigerant leak. Start by checking your thermostat mode and replacing a clogged filter before requesting a technician.
Air coming from vents feels lukewarm or room-temperature
Thermostat is set to Cool but house temperature keeps rising
Outdoor compressor unit is running continuously without cooling
Ice buildup noticed on copper refrigerant lines or air handler
Clogged or Filthy Air Filter: Restricts airflow over the evaporator coil causing freeze-ups.
Thermostat Settings: Set to 'ON' instead of 'AUTO', or accidentally switched to Heat mode.
Refrigerant Leak: Loss of chemical coolant lowers cooling capacity dramatically.
Tripped Breaker or Blown Fuse: Outdoor unit loses power while indoor blower stays on.
Faulty Compressor or Capacitor: Mechanical failure prevents the cooling cycle from starting.
Check Thermostat: Verify mode is set to 'COOL' and temperature is set at least 3 degrees below current room temp.
Inspect Air Filter: Slide out the filter and replace if visibly covered with dust or dirt.
Verify Circuit Breakers: Check both indoor and outdoor breaker switches; reset once if tripped.
Clear Outdoor Unit: Ensure at least 2 feet of clear space around the exterior condenser unit.
DANGER: High voltage electrical components and high-pressure chemical refrigerants pose serious hazards. Do not attempt to open electrical panels or handle refrigerant lines yourself. Turn off power at the breaker immediately if you smell burning electrical odors or spot active electrical sparks.
Contact an emergency HVAC professional if replacing the filter and checking thermostat settings fails to restore cool air, if you detect electrical burning smells, if refrigerant lines show ice buildup, or if your outdoor unit makes grinding noises.