Sudden AC failures usually come down to a short list: a tripped breaker, a clogged filter that froze the coil, a failed capacitor, a full condensate pan shutting the system off on a safety, or a thermostat problem. Several of these you can check yourself in five minutes.
Check the Breaker First
Air conditioners have two circuits — one for the outdoor unit and one for the indoor blower. Check both.
A tripped breaker is not always visually obvious. Flip it fully off, then back on. If it trips again, stop resetting it. The breaker is responding to a real electrical condition, and repeatedly resetting it is how an electrical fault becomes a fire risk.
Also look for the service switch near the indoor unit. It looks like an ordinary light switch, and in garages and utility rooms it gets flipped by accident with real regularity.
Check the Filter and Look for Ice
A clogged air filter restricts airflow across the evaporator coil. The coil gets too cold, freezes into a block of ice, and the system stops cooling entirely.
If you see ice on the refrigerant lines or the indoor coil, turn the system off — fan only if your thermostat allows — and let it thaw completely. Running with a frozen coil risks sending liquid refrigerant back to the compressor, which turns a filter problem into a system replacement.
Replace the filter while it thaws. In a Hill Country summer, when the system runs eighteen hours a day, filters load far faster than the package interval suggests.
Check the Condensate Drain
Your air conditioner removes gallons of water a day in this climate, and that water leaves through a small drain line that reliably clogs with biological growth.
Most systems have a float switch that shuts the unit off when the drain pan fills, precisely so it does not overflow into your ceiling. That safety working correctly presents as “my AC quit for no reason.”
If you find standing water in the pan, that is your answer. It is a routine fix, but it needs doing rather than bypassing.
Check the Thermostat
Confirm it is set to COOL and the setpoint is below room temperature. Replace the batteries if it uses them — a dying battery produces erratic behaviour well before a blank screen.
If the display is blank entirely, check the breaker and the door panel on the indoor unit; many systems will not run with the blower compartment door unlatched.
The Capacitor
If the outdoor unit is humming but the fan blade is not turning, that is usually a failed capacitor.
Turn the system off. A compressor attempting to start against a failed capacitor draws locked-rotor current, and a compressor running without the condenser fan overheats fast. This is the single most common way an inexpensive part destroys an expensive one.
Capacitors are not a homeowner repair — they hold a charge after power is removed.
What It Might Be Beyond That
Refrigerant loss, which means a leak, since refrigerant is not consumed. A failed contactor. A blower motor. A control board.
All of these are standard AC repair items, and most are found in advance during maintenance.
Why It Happened Now
Failures cluster on the hottest days for a reason. A marginal component — a drifting capacitor, worn bearings, slightly low charge — carries a light load without complaint in April.
Then the first hundred-degree week arrives, the system runs continuously, and the weak component gives out. That is also when every HVAC company in the county is booked, which is the practical argument for spring AC maintenance.
If You Need Help Now
Our emergency AC repair line runs around the clock, and members of our Care Club maintenance plan get priority dispatch during the weeks when everyone is calling at once.
Contact 72 Degrees or call (830) 468-5316.
