You press the thermostat down to 72, wait... and nothing happens. No fan, no compressor hum, no air from the vents. A completely dead AC system is different from one blowing warm air — and the causes are usually different too. Before you assume the worst, here's what Central Texas homeowners should check.
Check These First (5 Minutes, No Tools)
Thermostat batteries. If your thermostat screen is blank or dim, replace the batteries. Many digital thermostats run on AA or AAA batteries, and when they die, the thermostat can't send a signal to your AC. This is the #1 most overlooked cause of a "dead" AC system.
Thermostat settings. Make sure it's set to "cool" (not "off" or "heat") and the temperature is set below the current room temperature. Someone in the house may have changed it. Also try switching from "auto" to "on" for the fan — if the fan runs but the AC doesn't engage, that narrows the problem.
Circuit breakers. Your AC system uses two breakers — one for the indoor air handler and one for the outdoor condenser. Check your electrical panel for any tripped breakers. A tripped breaker will be in the middle position between ON and OFF. Flip it fully to OFF, then back to ON. If it trips again immediately, stop — there's an electrical issue that needs a professional.
The disconnect switch. There's a small metal box on the wall near your outdoor AC unit called the disconnect. It contains a pull-out switch or fuses. Sometimes this gets bumped, pulled out during maintenance and not replaced, or the fuses inside blow. Check that it's fully engaged.
The float switch. If your air handler has a drain pan, there's often a safety float switch that shuts off the AC when the pan fills with water (to prevent water damage). If your condensate drain is clogged, the pan fills, the switch triggers, and your AC won't run. Check for standing water in the drain pan under your air handler.
Common Causes That Need a Professional
Failed capacitor. The capacitor is a small cylindrical component in your outdoor unit that stores the electrical charge needed to start the compressor and fan motors. When a capacitor fails, the AC simply won't start — you might hear a clicking sound or a faint hum, but nothing kicks on. Capacitors fail frequently in Texas due to the extreme heat. Replacement typically runs $150–$300 installed.
Contactor failure. The contactor is an electrical switch inside the outdoor unit that engages when the thermostat calls for cooling. Over time, the contacts can pit, corrode, or weld together. When a contactor fails, the signal from the thermostat never reaches the compressor. This is a common repair — usually $150–$250 including parts and labor.
Blown fuse in the disconnect. The disconnect box near your outdoor unit often contains cartridge fuses. These can blow during a power surge or if the system draws too much current. A technician can test and replace these quickly.
Compressor failure. If the fan on the outdoor unit spins but the compressor doesn't engage, or if the unit tries to start and immediately shuts off, the compressor may be failing. On older systems (10+ years), compressor replacement is often not cost-effective — a full outdoor unit replacement may make more sense.
Wiring or control board issue. Rodents, corrosion, and age can damage wiring between the thermostat, air handler, and condenser. A bad control board in either the indoor or outdoor unit can also prevent the system from starting. These require a technician with diagnostic tools to identify.
What About the Warranty?
If your AC system is less than 10 years old, check your warranty paperwork before authorizing any repair. Many manufacturers cover the compressor for 10 years and other parts for 5 years. Kimco can verify your warranty status during the service call — we work with all major brands.
Texas Heat Makes This Urgent
In Central Texas, a dead AC isn't just an inconvenience — it's a health risk during summer. Indoor temperatures can exceed 100°F within hours when the system goes down. If you've checked the basics above and your AC still won't turn on, don't wait. The longer the system sits idle in extreme heat, the harder it works when it finally restarts, which can cause additional damage.
At Kimco Plumbing & Air, we provide AC diagnostics and repair across Central Texas — from Georgetown and Hutto to Bastrop, Bryan, and everywhere in between. Flat-rate pricing on every repair, no overtime charges, and same-week scheduling. Call (737) 260-7255.