Why Is My AC Blowing Warm Air? Here’s What It Could Be
There’s nothing more frustrating than coming inside on a blazing hot Southern California afternoon, turning on your air conditioner, and expecting a wave of cool relief—only to be met with warm air blowing through the vents. It’s more than just uncomfortable—it’s a clear sign that something is wrong. And in the middle of a heatwave, the last thing you want is an AC system that isn’t pulling its weight.
Warm air coming from your AC can be caused by a number of issues, some minor and easy to fix, others more serious and requiring professional attention. Whether it’s a faulty thermostat setting, a dirty filter, or a bigger mechanical problem, one thing is certain: the sooner you address it, the faster you can get your comfort back.
At Shalom Heating & Air, we’ve helped hundreds of homeowners across Anaheim, Long Beach, Tustin, and surrounding areas get their cooling systems back on track. Our trained technicians know how to spot and resolve these issues quickly—so you’re not left sweating it out.
In this article, we’ll walk you through the most common reasons your AC might be blowing warm air and explain what you can do—whether it’s a DIY fix or a call to your local HVAC pros. Let’s get started.
1. Incorrect Thermostat Settings
It might sound simple, but one of the most common culprits is the thermostat. Make sure it’s set to “cool” and not just “fan.” When in “fan” mode, your system moves air without running the compressor—meaning no actual cooling happens. Also, check that the temperature is set lower than the current room temp.
Warm air coming from your AC can be caused by several issues, including thermostat errors, clogged filters, low refrigerant, or frozen coils. Faulty ductwork or electrical problems may also be to blame, and professional diagnostics can quickly pinpoint the exact cause.
2. Dirty Air Filters
A clogged air filter can restrict airflow and cause the system to overheat or freeze up. Both conditions reduce cooling performance and can lead to warm air blowing through your vents. Filters should be cleaned or replaced every 1–2 months during heavy usage seasons.
3. Refrigerant Leak or Low Levels
Refrigerant is essential for absorbing heat from your indoor air. If levels are low—often due to a leak—your system can’t cool properly. Signs of low refrigerant include warm air, ice on the refrigerant line, and a hissing noise. This issue must be handled by a licensed HVAC technician.
4. Electrical or Compressor Issues
If your outdoor unit isn’t running, the compressor may have tripped a breaker or failed. Without the compressor, your system can’t transfer heat outdoors. A broken capacitor, faulty wiring, or worn-out components could be to blame. Don’t attempt to reset or repair electrical components yourself—call a professional.
5. Frozen Evaporator Coils
When evaporator coils freeze, air can’t properly pass through to be cooled. This usually happens from poor airflow (often caused by dirty filters) or low refrigerant. You might notice water leaks or visible ice on the unit. Turn off your AC and call a technician to safely thaw and fix the root cause.
6. Ductwork Problems
Leaks or damage in your ductwork can allow warm air from attics or crawlspaces to mix with your cooled air—or bypass cooling altogether. If only some rooms are affected, your ducts may be to blame.
When to Call the Pros
If basic fixes like adjusting the thermostat or changing the filter don’t restore cool air, it’s time to call Shalom Heating & Air. We offer fast, honest diagnostics and same-day repairs across Anaheim, Bellflower, Brea, Buena Park, Cerritos, Cypress, Downey, Garden Grove, La Palma, Long Beach, Norwalk, Orange, and Tustin.
We’ll find the issue, explain your options, and get your comfort restored without pressure or upsells. Our licensed technicians are trained on all makes and models and carry the tools needed to get your AC back to peak performance quickly.
Stay Cool in the Heat
Don’t suffer through another hot day with weak or warm airflow. If your AC is underperforming, schedule a service visit today and let us bring the cool back to your home. Contact Shalom Heating & Air for expert AC repair in Southern California—because comfort should never be optional.
