man fixing ac

June 24, 2025

You lower the thermostat and wait for that refreshing blast of cool air … But instead, all you get is a wave of warm air filling the room. 

Something’s not right if your AC is pumping out warm air, and it could be an early sign of a more serious problem.

At Heat Wiser, we understand how frustrating it can be when your cooling system isn’t performing as it should. Here’s a closer look at what might be causing it to blow warm air and how to get things back on track.

 1. Your Thermostat Settings Need a Second Look

It sounds simple, but one of the first things to check is your thermostat. Sometimes, it’s just a case of accidental settings.

Things to check:

  • Is the thermostat set to “cool” instead of “heat” or “fan”?
  • Is the temperature set lower than the current room temperature?
  • Have the batteries been changed recently?

What it means: If your thermostat isn’t correctly communicating with your system, your AC can’t cool properly. This is a quick fix, but it’s often overlooked.

2. Low Refrigerant Levels or a Leak

Refrigerant is the lifeblood of your air conditioning system. If your system is low on refrigerant from a leak or because it wasn’t filled properly, it prevents your AC from absorbing heat and makes it blow out warm air instead.

Signs of low refrigerant:

  • Reduced cooling efficiency
  • Ice buildup on the indoor or outdoor coil
  • Hissing or bubbling noises from the unit

What it means: A refrigerant issue is not something to ignore. Left unchecked, it can damage the compressor and lead to a much costlier repair. This is a job for a certified HVAC technician, and Heat Wiser is happy to help!

3. Dirty or Clogged Air Filters

Your AC needs clean, unrestricted airflow to work properly. A clogged air filter can block that airflow, making your system work harder, and ultimately leading to poor cooling performance.

What to look for:

  • Reduced airflow from vents
  • Increased dust in the home
  • AC cycles more frequently than usual

What it means: If your air filter hasn’t been changed in over a month, it’s time. In fact, we recommend checking it monthly, especially during the summer months. 

4. Electrical Issues or a Tripped Breaker

Air conditioning systems rely on multiple electrical components working together. If your outdoor condenser unit loses power due to a tripped breaker, faulty capacitor, or wiring problem, the cooling cycle can’t be completed properly.

How to identify the problem:

  • Indoor fan runs, but no cool air comes out
  • Outdoor unit isn’t making noise or spinning
  • Circuit breaker keeps tripping

What it means: Your indoor air handler may still be running, but without the condenser operating, warm air is all you’ll ever get. Fixing it could be as easy as resetting the breaker, or it might call for expert repair.

5. Dirty Condenser Coils

Your outdoor unit releases the heat pulled from your home. If those condenser coils are covered in dirt, grass, or debris, they can’t do their job effectively.

Common signs:

  • AC runs constantly but doesn’t cool
  • Unit feels hot to the touch
  • Higher than normal energy bills

What it means: A dirty condenser coil reduces system efficiency and increases wear on components. While professional cleaning during seasonal maintenance is essential, doing some simple DIY upkeep between your biannual tune-ups can make a big difference. It’s a lot easier than you think!

6. Leaky or Disconnected Ductwork

In some cases, the AC is cooling properly, but that cool air isn’t reaching your rooms. Leaky ducts or disconnected joints can let conditioned air escape into your attic or crawl space.

Things to keep an eye on:

  • Warm or uneven temperatures in certain rooms
  • Whistling noises from vents
  • Higher utility bills without explanation

What it means: Ductwork issues are especially common in older Syracuse homes. A duct inspection from Heat Wiser can identify and fix these problems to restore full system performance.

7. Your System Is Due for a Tune-Up

The secret to a well-functioning AC is consistent preventative maintenance. During a tune-up, a technician can catch small issues before they turn into major breakdowns.

Maintenance includes:

  • Cleaning the coils and filters
  • Checking refrigerant levels
  • Inspecting electrical connections
  • Verifying airflow and thermostat calibration

What it means: Haven’t had an AC tune-up in over a year? Don’t wait any longer. Regular service can help your system last longer and cool more effectively, especially during hot NY summers.

8. The System Is Old or Undersized

Even well-maintained AC systems wear out eventually. If your unit is more than 10–20 years old or not properly sized, it may no longer meet your cooling needs.

Signs of an aging unit:

  • Frequent breakdowns or repairs
  • High energy bills
  • Inconsistent temperatures throughout the home

What it means: It might be time to consider replacing your unit. Heat Wiser offers free estimates on system installations and can help you choose an energy-efficient model that’s right for your home and budget.

Keep it cool with Heat Wiser

Warm air coming from your AC? Stay calm and call Heat Wiser. Our skilled team will diagnose the issue fast and help get your home cool again.

Why we’re the HVAC experts you can count on:

With more than 18 years of experience and a commitment to quality, we’re proud to be the go-to HVAC team for Syracuse and the surrounding areas.

Schedule your AC service or seasonal tune-up today!