Few things are worse than coming home in a Central Texas summer to an AC that's pushing warm air. When it's 105 outside, you need answers fast — not a runaround. The good news: some causes are simple enough to fix in five minutes, while others need a licensed technician. Here's how to tell the difference and get your cool air back.
Key Takeaways
It sounds obvious, but it's the number-one culprit. If your thermostat is set to \"fan only\" or \"heat\" instead of \"cool,\" the system will blow air without cooling it. Someone in the house may have bumped the setting, or a power blip could have reset it.
Austin's oak pollen and cedar season can clog a filter in weeks. A blocked filter restricts airflow over the evaporator coil, causing the system to lose cooling capacity. If the filter looks gray or matted, that's your problem.
Low refrigerant means the system can't absorb enough heat from indoor air. You might notice ice forming on the outdoor unit or refrigerant lines. Refrigerant doesn't \"run out\" on its own — a leak means a connection or coil has failed and needs professional repair.
Your AC has two components: the indoor air handler and the outdoor condenser. If the breaker to the outdoor unit trips (common during Austin's summer power surges), the fan will still blow inside — but without any cooling.
The compressor is the heart of the cooling cycle. If it fails — or the capacitor that starts it burns out — the outdoor unit won't do its job. You might hear a humming or clicking sound from outside. This requires a licensed HVAC technician.
A sudden change usually points to a tripped breaker, a thermostat glitch, or a capacitor failure. If you were getting cold air earlier today and now it's warm, start by checking the breaker and thermostat before calling for service.
Yes. A severely clogged filter restricts airflow to the point where the evaporator coil can't absorb heat effectively. In Austin's high-pollen seasons, filters can clog in as little as two to three weeks. Check yours monthly during summer.
It depends on the cause. A filter change costs under $20. A capacitor replacement typically runs $150–$300. Refrigerant leak repair and recharge can range from $250–$1,500 depending on the location and severity of the leak.
If the system is running but not cooling, it's generally safe to run for a short time while diagnosing the issue. However, if you see ice on the lines or outdoor unit, shut the system off immediately — running it in that state can damage the compressor.