AC Running But Not Cooling in Las Vegas? Causes & What to Do

The short answer

If your AC runs but the air is not cold, the cause is almost always one of five things: restricted airflow (filter or dirty coils), a failed capacitor or contactor, low refrigerant from a leak, a dead compressor, or a ductwork problem dumping cool air into the attic. The filter and thermostat checks take you five minutes; everything else needs gauges and a multimeter.

Safe checks before you call

1. Thermostat — COOL mode, set at least 3°F below room temperature, fan on AUTO. Replace the batteries if it has them.
2. Filter — pull it and hold it to the light. If you cannot see through it, replace it. In Las Vegas dust season, filters load up faster than the calendar suggests.
3. Breaker — check the AC breaker in your panel. One reset is fine; if it trips again, stop and call.
4. Outdoor unit — is the fan spinning? Is the coil matted with dust and cottonwood fluff? Gently rinse the coil with a garden hose (power off first); never a pressure washer.
5. Ice check — ice on the copper lines or the unit means turn cooling OFF, run the fan, and let it thaw fully before retesting.

Cause → part → repair

When to stop and call

Stop DIY at the electrical panel door. If the basic checks do not restore cold air, the cause involves 240-volt components or refrigerant — both genuinely hazardous without training, and refrigerant handling requires EPA certification. One more reason to stop early in Las Vegas: running a system that cannot cool properly (low charge, failing capacitor) forces the compressor to overheat, and compressors die from exactly this kind of neglect.

What the technician will do

Expect a 30–60 minute diagnosis: refrigerant pressures and temperature split across the coil, capacitor and contactor test, compressor and fan amp draw, airflow check, and a look at the filter, coil and drain. You get the failed part identified and a flat price before any work. Most causes on the table above are van-stocked parts fixed in the same visit — call +1 (725) 360-1290 and describe the symptom.

Frequently asked questions

Why is my AC running but not cooling the house?

The most common causes, in rough order of frequency in Las Vegas: a dirty filter or matted condenser coil restricting heat transfer, a failed capacitor or contactor leaving the compressor off while the fan runs, low refrigerant from a leak, or a failed compressor. Start with the filter and thermostat; the rest needs a technician with gauges and a meter.

How do I fix my AC that is not cooling?

Safely, you can: set the thermostat to COOL below room temperature, replace the filter, clear debris from the outdoor unit, check the breaker, and — if the coil is iced — turn cooling off and run the fan to thaw it. If none of that restores cold air, stop: the remaining causes involve 240V electrical parts and refrigerant, which are not DIY work.

Is it an emergency if my AC is running but not cooling in Las Vegas?

It can be. If indoor temperature is climbing past the mid-80s and the household includes infants, elderly family members, medical conditions or pets, treat it as urgent and call. Otherwise, turn the system off to prevent compressor damage and call for the next available appointment — running a sick system can turn a cheap repair into a compressor replacement.

How much does it cost to fix an AC that is not cooling?

It depends entirely on the cause: a capacitor or contactor runs $100–$400, a fan motor $200–$700, leak repair plus recharge $400–$1,500, and a compressor $1,300–$2,800. Diagnosis ($75–$200) identifies which one you are looking at. Sourced ranges: cost guide.

Can low refrigerant cause the AC to run but not cool?

Yes — it is one of the most common causes. Refrigerant is not consumed; low charge means there is a leak. The fix is find-and-repair the leak, then recharge — never just a top-off.