AC repair in Austin is a summer-long business. When a system quits in July, the house can climb into the high 80s by evening, and the questions come fast: is it the thermostat, the breaker, the unit outside, or something expensive? This page explains what the common symptoms usually mean, what you can safely check yourself, and what a careful technician should do once they arrive.
Austin AC Service does not repair air conditioners. It is a free phone line. When you call (737) 378-9016, an automated assistant asks whether the problem is cooling or heating, takes your name, number, city or ZIP and a description of what the system is doing, then transfers you to an independent, locally owned HVAC company that serves your part of the Austin area. That company diagnoses the system, gives you a price and does the work. You pay it directly.
What an Austin summer does to an air conditioner
The official Austin weather station at Camp Mabry averages about 29 days a year at 100 degrees or hotter under the 1991 to 2020 normals. In 2023 it logged 80, including a record run of 45 days in a row in July and August. Manual J, the load calculation contractors use to size a home system, designs for 75 degrees indoors when it is about 96 outside in Austin, a temperature exceeded only about 1 percent of the hours in a typical year. On a 104-degree afternoon even a healthy, correctly sized unit runs almost without stopping and may sit a degree or two above the setting.
That long run time is what finds the weak part. Capacitors that have been baking in a metal cabinet in full sun lose strength. Outdoor coils packed with cottonwood fluff and grass clippings cannot shed heat. Drain lines that sat dry all winter grow algae and back up. Most July breakdowns are a small part that finally gave out under load, which is why the diagnosis matters more than anything else on the bill.
What the symptom usually points to
These are the patterns HVAC technicians see most often. They are a starting point for the conversation, not a diagnosis. Only someone with meters and gauges on the system can tell you which part has actually failed.
| What you notice | Common causes | Safe to check yourself |
|---|---|---|
| Air from the vents is warm or barely cool | Clogged filter, frozen indoor coil, dirty outdoor coil, low refrigerant from a leak, failed outdoor fan | Thermostat set to Cool and below room temperature; filter; outdoor unit running |
| Outdoor unit hums but the fan does not spin | Weak or failed capacitor, seized fan motor, failing compressor | None beyond the breaker. Turn the system off at the thermostat and call. |
| Nothing runs at all | Tripped breaker, thermostat with dead batteries, a drain safety switch that shut the system off, failed control board | Thermostat batteries and mode; reset a tripped breaker once |
| Ice on the copper lines or the indoor coil | Restricted airflow (filter, blower, closed vents) or low refrigerant | Turn cooling off and let it thaw with the fan on; check the filter |
| Water dripping from a ceiling or around the indoor unit | Clogged condensate drain, cracked or rusted drain pan, failed safety switch | Turn the system off. Look at where the drain line exits outside. |
| Breaker trips again after a reset | Electrical fault, shorted compressor or motor | No. Leave the breaker off and call. |
| Short cycling (on and off every few minutes) | Oversized system, thermostat in a bad spot, low refrigerant, overheating compressor | Thermostat location (sun, lamp or supply vent nearby) |
Before you call: five safe checks
A surprising number of no-cooling calls turn out to be something you can sort out in ten minutes. None of these involve opening a panel or touching wiring.
- Thermostat. Make sure it is set to Cool, not Heat or Off, and a few degrees below the room temperature. If the screen is blank or dim, replace the batteries.
- Breakers. The indoor air handler and the outdoor condenser are usually on separate breakers. If one is tripped, reset it once. If it trips again, leave it off. That is an electrical fault for a technician.
- Air filter. A filter caked with dust and spring cedar or oak pollen starves the system of air and can freeze the coil. Swap it for a clean one of the same size.
- Outdoor unit. Look, do not reach in. Leaves, grass clippings or a shrub pressed against the coil block airflow. Clear debris from around the outside of the cabinet with the power off.
- Condensate drain. Find where the small PVC drain line exits the house, usually near the outdoor unit or out of an attic soffit. If it is dry while the system is running in summer, or there is a float switch on the indoor unit with water in its pan, the drain may be blocked and the switch may have shut the system off on purpose.
Checked all five and it still is not cooling? Call and describe exactly what you saw. The company you are put through to will know which questions to ask.
When to turn it off and stop trying
Some symptoms mean that running the system longer can turn a modest repair into a large one. Switch the thermostat to Off and call if you see any of these.
- Ice on the refrigerant lines or indoor coil. Running a frozen coil can send liquid refrigerant back to the compressor.
- The outdoor unit hums or buzzes but the fan is still. The compressor may be straining to start and overheating.
- A burning, electrical or hot-plastic smell. Turn the system off at the thermostat and the breaker.
- Water coming through a ceiling. Shut the system off, put a bucket under the leak and protect anything below it.
- A breaker that trips twice. Repeated trips are a fault, not bad luck.
What a proper AC diagnosis includes
You do not need to understand the readings, but you can tell a careful visit from a rushed one. A good technician works through the system in an order that makes sense and explains what they found.
- Airflow first. Filter, blower, coil and ducts. The Air Conditioning Contractors of America points out that refrigerant readings mean little on a system that is not moving the right amount of air, so this comes before the gauges.
- Electrical tests under load. Capacitor values against the rating printed on the part, contactor condition, voltage and amperage on the compressor and fan motors.
- Refrigerant charge measured, not guessed. Pressures and line temperatures compared to the manufacturer's charging method for that specific system. If it is low, the next question is where the leak is.
- Temperature split in context. Many technicians expect roughly a 15 to 20 degree drop between return and supply air, but ACCA warns that the right number depends on humidity, airflow and the system, so it is one clue rather than a pass or fail.
- Drain and safety switches. The primary drain cleared and the float switch tested, especially on attic units.
- A written finding and price. What failed, why, what the repair costs, and what else they noticed that is not urgent.
Attic air handlers and ceiling leaks
A large share of Austin-area homes built in the last few decades put the indoor unit and ducts in the attic. In August that attic can be far hotter than the outdoor air, which makes the equipment work harder and makes leaky ducts expensive. It also means that when the condensate drain clogs, the water has only one place to go: down through the drywall.
Building codes based on the International Residential Code call for a backup when a cooling coil sits where an overflow would damage the house, usually a secondary drain pan with its own line or a float switch that shuts the system off. If you have an attic unit, ask the technician to show you which one you have and whether it works. A secondary drain that ends above a window and suddenly starts dripping is a warning sign that the main drain is blocked.
Repair or replace?
Most AC repair calls end with a repair. Replacement only belongs in the conversation when the numbers or the parts say so. If a company leads with replacement, ask it to price the repair too.
Usually worth repairing
- A failed capacitor, contactor, fan motor or thermostat
- A clogged drain or failed float switch
- A small, reachable leak on a newer system
- A system under about ten years old that has been maintained
Worth pricing a replacement too
- A failed compressor on an older system
- A leaking indoor coil on a system near the end of its life
- An R-22 system: production of R-22 ended in the United States in 2020, so recharging it is expensive
- Repeated repairs on the same unit in the same season
If your system uses R-410A, it can still be repaired and recharged. New systems built since 2025 use newer refrigerants such as R-454B, and the federal deadline that would have stopped installs of older R-410A equipment after January 1, 2026 was removed by the EPA in 2026. Nobody should tell you a working R-410A system must be replaced because of a deadline. The free refrigerant guide explains the whole change.
Three questions to ask before you approve a repair
What is your TDLR license number?
Every company the line connects you with holds a Texas air conditioning and refrigeration contractor license, and you can confirm any company's license yourself at tdlr.texas.gov in about a minute.
Can I have the diagnosis and price in writing?
The quote should name the failed part, the labor and any refrigerant, with a total, before work starts. If the diagnostic fee is credited toward the repair, it should say so.
Is repair an option here?
Ask this before any replacement is quoted. A straight answer, with the repair price and the replacement price side by side, is the sign of a company worth keeping.
Keeping the next repair away
A few habits make a real difference in this climate. Change the filter on schedule, and more often during cedar season in winter and oak pollen season in spring. Keep two feet of clear space around the outdoor unit and rinse the coil gently with a garden hose from the inside out after the cottonwood season. Set the thermostat and leave it: the U.S. Department of Energy suggests 78 degrees when you are home and need cooling, and Austin Energy makes the same recommendation. Big setbacks on a 105-degree afternoon just make the system play catch-up in the evening. And book a spring tune-up before the first heat wave rather than during it.
- Call any hourAn automated assistant answers (737) 378-9016 and asks whether it is about cooling or heating.
- Describe the problemGive your name, a callback number, your city or ZIP and what the system is doing.
- Get put throughThe call goes to an independent, locally owned HVAC company, which hears a short summary before it picks up.
- Deal with them directlyThat company diagnoses, quotes, does the work and is paid by you. If it cannot answer, it gets your details to call back.
How this line works: Austin AC Service is a free phone line, not an HVAC company. It does not repair, install, quote or schedule work and holds no license. Calls are transferred to independent, locally owned HVAC companies that hold Texas air conditioning and refrigeration contractor licenses. Those companies may pay Austin AC Service a referral fee. You never pay the line. How it works.
Check any license yourself. Texas air conditioning and refrigeration contractors are licensed by the Texas Department of Licensing and Regulation. Ask for the license number and look it up at tdlr.texas.gov (opens in a new tab).
Related services
Emergency AC and Heating Repair
No cooling in a 100-degree week or no heat in a freeze. What counts as an emergency, what is safe to check first, and when to leave the house.
AC Installation and Replacement
Repair or replace, sizing by load calculation, the R-454B refrigerant change, permits, and Austin Energy rebates.
HVAC Maintenance and Tune-Ups
A spring cooling check before the heat and a fall heating check before the first freeze, and what a real tune-up includes.
AC repair across the Austin area
The line answers for Austin and the surrounding cities. Each area page covers what is different about homes, utilities and permits there.
- All Austin-area service areas
- South Austin
- Round Rock
- Cedar Park
- Pflugerville
- Georgetown
- Leander
- Kyle
- Hutto
- Buda
- Lakeway
- Manor
- Dripping Springs
Before you hire anyone, the guide to choosing an HVAC company in Austin explains how to check a license and read a quote.