AC running but blowing warm air? Call 702-556-4812 any time, day or night. A licensed technician diagnoses it and gives you a written price before any work starts.
This is the call we get most in a Las Vegas summer. The good news is that some causes take five minutes to fix yourself. The rest need a technician, and a few mean you should shut the system off now to avoid a much bigger repair.
Check these four things first
Before you call anyone, spend two minutes on these. They solve a fair number of warm-air calls, and they cost you nothing.
- The thermostat. Make sure it is set to COOL, not HEAT or EMERGENCY HEAT, and that the fan is set to AUTO, not ON. On AUTO the fan only runs when the system is actually cooling. Left on ON, it blows room-temperature air between cycles, and that alone feels like a broken AC.
- The air filter. Pull it out and hold it up to a light. If you cannot see light through it, that is your problem, or a large part of it. A blocked filter starves the system for air and can freeze the indoor coil solid.
- The breaker. Most homes here have two: one for the indoor air handler or furnace, one for the outdoor condenser. If the outdoor one has tripped, the indoor fan keeps blowing but nothing is cooling the air. Reset it once. If it trips again, stop and call us — a breaker that keeps tripping is telling you something is wrong electrically.
- The outdoor unit. Walk outside and look. Is the fan on top spinning? Is the unit buried in dust, cottonwood or oleander clippings? Can you hear a hum with no spin? A humming unit with a still fan usually means a failed capacitor.
Turn the system off if you see ice
If there is frost or ice on the copper lines at the outdoor unit, or on the indoor coil, switch the system to OFF and set the fan to ON. Running an iced-up AC pushes liquid refrigerant back to the compressor, and the compressor is the single most expensive part in the system. Let it thaw for a few hours with just the fan running, then call us. Ice is almost always a symptom of low airflow or low refrigerant, and both need to be looked at.
What it usually turns out to be
A failed capacitor
The most common single failure we find, and the most common cause of an outdoor unit that hums but will not start. The capacitor gives the motors the jolt they need to spin up. In 110°-plus heat they cook and fail. It is a small part and one of the less expensive repairs.
A burned contactor
The contactor is the electrical switch that tells the outdoor unit to run. Its contacts pit and burn over years of cycling. Symptoms look identical to a capacitor failure from the outside, which is why the diagnosis matters.
Low refrigerant from a leak
Refrigerant is not consumed. If it is low, it leaked out. Adding more without finding the leak means you will be making this same call next summer, and you will pay for the refrigerant twice. We look for the leak first and tell you what it will take to fix it. If your system was installed in 2025 or later it likely uses R-454B or R-32 rather than the older R-410A, which changes both the handling and the cost.
A dirty condenser coil
The outdoor unit sheds your home’s heat into the air outside. When the coil is packed with dust and landscaping debris — and in this valley it packs fast — it cannot do that. The system runs constantly, cools poorly, and wears out early. Cleaning it is routine maintenance, not a repair.
A failing compressor
The expensive one. A compressor that has shorted or seized usually means deciding between a major repair and a replacement. On a system over about 12 years old, replacement is often the better value, and we will show you both numbers in writing rather than steering you.
Duct problems in the attic
Plenty of valley homes run their ductwork through an attic that hits 150° in July. If a duct has come loose or its insulation has failed, the air leaves the unit cold and arrives at the vent warm. This one is easy to miss, because the equipment itself tests fine. If some rooms are far worse than others, suspect the ducts.
What it costs to find out
No service-call fee for a limited time (normally $125, credited to your repair). Our $89 offer is the whole-home check-up. You approve a written price before we touch anything. Care Plus members pay $24.99 a month and have a $0 diagnostic fee with no after-hours charges.
When it is worth calling right away
Call without waiting if the house is over 85° and climbing, if anyone at home is elderly, very young or has a health condition, if you smell burning, or if the breaker keeps tripping. We answer 24 hours a day. Same-day service when available.
Common questions
Why is my AC running but not cooling?
The most common causes are a failed capacitor in the outdoor unit, a burned contactor, low refrigerant from a leak, a frozen indoor coil, or a dirty condenser coil. A blocked air filter or a thermostat fan left on ON can also make the air feel warm. Start with the filter, the thermostat setting and the outdoor unit, then call a technician.
Should I turn my AC off if it is blowing warm air?
Yes, if you see ice on the refrigerant lines or the indoor coil, or if the breaker keeps tripping. Running an iced system can damage the compressor, which is the most expensive part to replace. Switch the system to OFF, set the fan to ON to help it thaw, and call us.
How much does it cost to fix an AC that is not cooling?
It depends entirely on the cause. A capacitor is one of the least expensive repairs; a compressor or a coil leak is at the other end. There is no service-call fee for a limited time (normally $125, credited to your repair), and you approve a written price before any work starts.
Can low refrigerant be topped off?
It can, but refrigerant is not used up during normal operation. If a system is low, it has a leak, and adding refrigerant without repairing the leak means the same failure will come back. We find the leak and price the repair before recommending a recharge.
How fast can someone come out in Las Vegas?
We answer 24 hours a day, 7 days a week across the valley. Same-day service when available.
My AC is over 12 years old. Repair or replace?
If a single repair costs more than roughly a third of a new system, or if the compressor or evaporator coil has failed, replacement usually makes more financial sense. We give you both prices in writing and tell you honestly which one we would choose.
Related: AC repair and maintenance · refrigerant leak repair · evaporator coil services · ductwork repair · 24/7 emergency AC service · AC replacement
Call 702-556-4812 24/7, or book online. Nevada HVAC license #0081345 · Plumbing license #0090251.