Why won't my AC turn on at all?

Start with the basics: check thermostat batteries, make sure it's set to cool, and inspect both circuit breakers (indoor and outdoor units). Also check for a clogged condensate drain, which can trip a safety float switch that shuts the system down. If none of those fix it, you likely have a failed electrical component like a capacitor or contactor, which requires a licensed HVAC technician.

What should I do if my AC fan is not spinning?

Turn the system off immediately to protect the compressor from overheating. The most common cause is a failed run capacitor, which gives the fan motor the energy boost it needs to start. A burned-out fan motor is also possible. Both repairs require a professional since capacitors store dangerous electrical charge.

Why does my AC keep turning on and off every few minutes?

This is called short cycling, and the most common causes are a dirty air filter, low refrigerant, an overheating compressor, or an oversized AC unit. Replace your filter first. If that doesn't fix it, stop running the system and call for service. Repeated short cycling can permanently damage the compressor.

How do I fix an AC that's frozen up?

Turn the AC off at the thermostat and set the fan to "on" to circulate warm air over the frozen coil. Wait 2 to 4 hours for the ice to melt. Don't chip at it. Replace the air filter while you wait. Once thawed, turn the AC back on. If it freezes again, you likely have a refrigerant leak that needs professional repair.

Why is my AC running all day but the house isn't getting cool?

Common causes include dirty condenser coils, low refrigerant, leaky ductwork, or an undersized system. Start by cleaning the outdoor coils with a garden hose and replacing the air filter. On extremely hot days (105 degrees or higher), even a properly working AC may struggle, as most systems are designed for a 20-degree temperature difference between indoor and outdoor temperatures.

Is a broken AC an emergency in San Antonio?

It can be. When temperatures exceed 100 degrees, a home without AC can reach dangerous indoor temperatures within hours. Young children, adults over 65, and people with chronic health conditions are most at risk. If you can't restore cooling quickly, go to a cooled public space and call for same-day or emergency HVAC service.

6 Emergency AC Problems in San Antonio: Why Your AC Isn't Working and What to Do

When your AC quits in a San Antonio summer, you need answers fast. Here are the six most common emergency AC problems we see, what you can check yourself, and when to call a pro.

Why Your AC Is Not Turning On

A completely dead AC is stressful, but it's often a simple fix. Check these first:

•Thermostat batteries: Dead batteries are the number one cause of a "dead" AC.
•Thermostat settings: Make sure it's set to "cool" with a target below the current room temp.
•Circuit breakers: Your AC has two breakers (indoor and outdoor). Reset a tripped breaker once. If it trips again, call a pro.
•Condensate drain: A clogged drain triggers a safety float switch that shuts everything off. Check for standing water in the drain pan.
•Outdoor disconnect box: Make sure the pull-out switch near your outdoor unit is properly seated.

If none of that works, you're likely dealing with a failed capacitor, contactor, or wiring issue. These need a licensed technician.

AC Fan Not Spinning: Causes and Fixes

If your outdoor unit is humming but the fan won't spin, turn the system off immediately. Without the fan, your compressor will overheat, turning a moderate repair into an expensive one.

•Bad capacitor: The most common cause. The motor hums but can't start without it.
•Burned-out fan motor: Motors wear out over time, especially in San Antonio heat.
•Contactor failure: This relay sends power to the outdoor unit. If it's stuck open, nothing runs.
•Debris: Sticks, leaves, or critter nests can physically block the blades.

Check for visible debris, but capacitor and motor repairs need a technician. Capacitors store dangerous electrical charge.

Why Your AC Keeps Turning Off (Short Cycling)

Short cycling means your AC runs for a few minutes, shuts off, then starts again. It never cools properly and puts serious strain on the compressor.

•Dirty air filter: Restricted airflow causes the system to overheat and shut down.
•Oversized AC unit: Cools the air near the thermostat too fast, then shuts off before the rest of the house catches up.
•Low refrigerant: Triggers the low-pressure safety switch.
•Overheating compressor: Dirty or blocked outdoor unit trips the high-pressure switch.

Replace your filter first and clear space around the outdoor unit. If it continues, stop running the system. Every short cycle wears down the compressor, and that's one of the most expensive repairs there is.

AC Freezing Up in Texas Heat

Ice on your AC when it's 100 degrees outside? It's more common than you'd think. The evaporator coil gets so cold that moisture freezes on contact, blocking airflow completely.

•Restricted airflow: Dirty filter, closed vents, or a blocked return.
•Low refrigerant: A leak drops the coil temperature below freezing.
•Blower motor issues: Not enough air moving across the coil.
•Running AC when it's cool outside: Temps below 60 degrees can cause the coil to freeze.

To fix it: turn the AC off, set the fan to "on" to blow warm air over the coil, and wait 2 to 4 hours. Don't chip the ice off. Replace the filter while you wait. If it freezes again after thawing, call a pro to check refrigerant levels.

Never keep running a frozen AC. It can burn out the compressor, and that's a $2,000 to $3,500 repair or a full system replacement.

Thermostat Not Working: Quick Fixes

The thermostat is the brain of your HVAC system. When it acts up, nothing works right. The good news: these are often the easiest fixes.

•Blank display: Replace the batteries. Even hardwired thermostats have backup batteries.
•Display on but AC won't respond: Switch off, wait 30 seconds, switch back to cool.
•Wrong temperature reading: Make sure the thermostat isn't in direct sunlight, near a lamp, or above a vent.
•Schedule not working: Check that time and date are correct after any power outage.

If your thermostat is over 10 years old, consider upgrading. Modern digital thermostats are more accurate and can save on energy bills. Just make sure it's compatible with your system.

AC Running Constantly but Not Cooling

The fan's blowing all day but the house won't cool down. That's frustrating and expensive. Here's what's usually going on:

•Dirty condenser coils: Coated outdoor coils can't release heat efficiently.
•Low refrigerant: A leak reduces cooling capacity. The system runs nonstop but never reaches the set temp.
•Leaky ductwork: ENERGY STAR says typical homes lose about 30% of conditioned air through duct leaks.
•Undersized system: Your AC may not have the capacity for your home, especially if you've added square footage.
•Extreme heat: On days above 105 degrees, most systems can only maintain about a 20-degree difference from outside temps.

Replace your filter, rinse the outdoor coils with a hose, and close blinds on sun-facing windows. If that doesn't help, have a technician check refrigerant levels and ductwork.

Don't Wait It Out

In San Antonio's triple-digit heat, a broken AC can become a health risk fast, especially for kids, seniors, and pets. If the quick fixes above don't work, head to a cooled public space and call for emergency service. And the best way to avoid all this? Change your filter monthly, schedule a spring tune-up, and don't ignore warning signs. A $89 tune-up beats a $3,000 compressor replacement every time.