Home / Before you call
AC not cooling? Check these first
Many "broken" air conditioners have a simple cause. These checks are safe for any homeowner. Anything beyond them is a job for a licensed technician.
Safe things to check
- Thermostat. Is it set to Cool, and below the room temperature? Replace the batteries if the screen is blank or dim.
- Breaker. Check the panel for a tripped AC or air handler breaker. Reset it once. If it trips again, stop and call a pro.
- Filter. A clogged filter can cut cooling sharply. Replace it.
- Frozen coil. Ice on the copper lines or indoor unit? Turn the system off and set the fan to On for a few hours to thaw it. Then replace the filter. If it freezes again, call a pro.
- Outdoor unit. Is it running? Is anything blocking it? Clear debris from around it.
- Drain line. Some systems shut off when the condensate drain backs up. If there's a float switch or water in the drain pan, the line likely needs clearing.
Turn it off and call a licensed pro if
- The breaker trips more than once
- You smell burning or see scorched wiring
- The outdoor unit hums but the fan doesn't spin
- Ice keeps coming back
- You hear grinding, screeching or banging
- There's an oily residue on the refrigerant lines, which may be a leak
Never open electrical panels inside the unit or handle refrigerant yourself. Capacitors can hold a dangerous charge even with the power off.