Why Is My AC Blowing Warm Air? | Phoenix HVAC Pros

If your AC is blowing warm air in Arizona, the most common causes are a thermostat set wrong, a tripped breaker, a clogged filter, a dirty outdoor unit, or low refrigerant from a leak. Some of these you can fix yourself in five minutes. The rest need a licensed tech, and in a Phoenix summer you want to know which is which fast.

I have been fixing air conditioners around the Valley for over 40 years, and warm air calls are the number one call we get from June through September. Here is exactly what I tell my own neighbors to check before they spend a dime, and what it means when those checks do not solve it.

First, Check These Three Things Yourself

Before you call anyone, walk through this quick list. About one out of every five warm air calls we run ends up being one of these, and I would rather save you the trip charge:

•      Thermostat settings. Make sure it says COOL, and the fan is on AUTO, not ON. When the fan is set to ON, it keeps blowing air between cooling cycles, and that air feels warm.

•      The breaker. Phoenix heat makes ACs work hard, and a breaker can trip. Check your panel for a breaker marked AC or condenser that is sitting in the middle. Flip it fully off, then back on, one time only. If it trips again, stop and call a pro.

•      The air filter. A filter choked with dust can freeze the system up, and a frozen coil ends up blowing warm air. If the filter looks gray and furry, swap it, then give the system a few hours with the unit off so any ice can melt.

Why Is My AC Blowing Warm Air? The Usual Suspects

If the simple stuff checks out, here is what we find most often when we open up a system. A dirty outdoor coil is a big one. Your outside unit has to dump heat into 110 degree air, and if the coil is caked with dust and cottonwood fluff, it just cannot do it. A failed capacitor is another. That is the little part that helps the compressor start, and our summer heat kills them by the truckload. And then there is low refrigerant. Your AC does not use up refrigerant like gas in a car. If it is low, it leaked out somewhere, and topping it off without fixing the leak is renting cold air, not buying a repair. Our AC repair techs put gauges on the system and tell you what is actually going on, with a flat quote before any work starts.

A Real Call From Last Month in Glendale

A gentleman in Glendale called us on a Saturday in July. His system was running nonstop but the house was stuck at 85. He had already been told by another outfit that he needed a whole new unit for twelve grand. Our tech found a capacitor reading half its rated value and an outdoor coil so dirty you could not see the fins. About an hour of work later, that same twelve-year-old unit was blowing 55 degree air at the vents. Not every story ends that cheap, but it shows why you want a diagnosis, not a sales pitch. That is also why we run our $109 service call with a flat quote up front, so you know the price before we turn a wrench.

The Honest Part: Sometimes Warm Air Means It Is Time

I will shoot straight with you. If your system is 15 years or older, uses the old R-22 refrigerant, and the fix involves a compressor or a big refrigerant leak, putting money into it is often throwing good money after bad. In that case the right move may be replacement, and we will tell you that plainly, along with a free estimate on a new system through our AC installation team. But we fix what can be fixed. Roughly seven out of ten warm air calls we run end in a repair, not a replacement. Anyone who jumps straight to selling you new equipment without showing you readings off your old one is not doing you a favor.

Get Cold Air Back Today - Call Western Sky Mechanical

An AC blowing warm air in Arizona is not something to wait out, especially with kids, older folks, or pets in the house. Western Sky Mechanical is family-owned, ROC licensed (#366148), and we answer 24/7 with no after-hours markup. You get a $109 service call with a flat quote, a 1-year parts warranty, and a 2-year workmanship guarantee. Call us at 602-767-5341 and we will get that warm air problem figured out. And if you want to catch these problems before summer, read our post on 5 signs your AC needs repair in Phoenix.

FAQ: Warm Air From Your AC

Why is my AC running but the house will not cool below 80?

It is usually working at partial strength. Common causes are a dirty outdoor coil, a weak capacitor, low refrigerant, or leaky ducts dumping your cold air into the attic. A proper diagnosis with gauges will pin it down.

Can I just have refrigerant added every summer?

You can, but I do not recommend it. Refrigerant only gets low because of a leak, and the leak usually gets worse. Finding and fixing it almost always costs less over two summers than repeated top-offs.

How fast can someone come out during a Phoenix heat wave?

We run 24/7 emergency service with no after-hours markup, and warm air calls with vulnerable folks in the house go to the top of the list. Call 602-767-5341 and tell us what you have got.