Today, we’re talking about something super important: when your air conditioner stops blowing cool air.

Imagine it’s super-hot outside, and your AC isn’t working right. Not fun, right? But don’t worry, we’re here to help you figure out why it’s happening and what you can do to fix it.

Our Indoor Comfort Team crew is dedicated to keeping our neighbors in St. Louis cool during these summer months.


We’re here to help you with 15 troubleshooting tips for your AC not blowing cool air before you call in the St. Louis professionals at Indoor Comfort Team.


  1. The first thing to check is the thermostat settings. Please double-check that the system is on and set to cool and that the temperature setting has not been inadvertently changed. You can also change out the batteries in the thermostat, especially if the thermostat is malfunctioning.

    If any settings are incorrect, make the appropriate adjustments and let the system kick back on. Give it a few minutes to adjust, and then check that cool air is blowing out from the vents. If you feel cool air, you’ve fixed the problem! If not, let’s move on with our troubleshooting.


  1. Very often, the fix is quite simple. Have you checked the air filter lately? A check of this may fix your problem. Turn the system off and remove your air filter for inspection.

    Since the air filter catches dust, dirt, and other airborne particles, a dirty air filter can block airflow and cause your AC to not blow cool air through your vents. If the air filter appears dirty, replace the filter and see if this fixes the issue.


  1. In some houses, the Furnace/AC unit is wired to a switch in your utility room. Double-check that no power switch in your utility room has been switched off.


  1. The next likely reason your AC is not blowing cool air is your circuit breaker. Often, there is a separate breaker for the indoor and outdoor AC units. Check to ensure all appropriate breakers are switched on.
  2. Lack of maintenance on your outdoor unit can cause many issues with your unit. Complete a visual inspection of the area and ensure at least 2 feet of space around the unit. You may need to remove leaves, branches, or debris around the unit. If you haven’t had your unit serviced recently, it may be a great time to call on the experts at the Indoor Comfort Team for a professional inspection and maintenance.

    We offer our VIP Club Plan for affordable maintenance bi-annually with multiple payment options. Learn more about our VIP Club Plan and its benefits here –


  1. Clearing away the leaves, branches, and other debris around the unit will also be helpful if you have a blocked condenser fan. The condenser fan brings air into the outdoor unit and through the condenser coil to pull heat from the home. If there is debris accumulated between the fans, this can clog the coil and reduce energy efficiency, and lead to your AC not blowing cool air.
  2. A dirty condenser coil may also be causing the issue. The condenser coil wraps around the outdoor unit condenser and can also accumulate dirt, filth, and debris, which will restrict important heat transfer.


  3. Check your outdoor disconnect. This box is mounted near the outside AC unit and is a safety feature that can shut off the electrical unit. If the disconnect power is shut off, turn it back on. You can also check for damaged or faulty issues that may be causing an issue and will require a call to the professionals at the Indoor Comfort Team.


  1. A dirty or frozen evaporator coil may be the problem causing your AC to run but not cool the air.

    When an evaporator coil is dirty, it blocks the heat transfer from the air to the refrigerant and causes the coil to freeze. Some signs of a frozen evaporator coil are frost formed on the copper refrigerant tubing, increased utility bills, and the system not adequately cooling. If this is the case, turn the AC off and allow your system to run on ‘fan only’ until the coil is no longer frozen, and then turn the AC back on.


  1. A dirty indoor fan motor can also create problems leading your AC to not blow cool air.

    When this fan is dirty, the fan cannot pull enough hot air into the unit to cool your home adequately. This fan cleaning can be completed by one of our HVAC pros. Give us a call (314)230-9542 and we’d be happy to help!


  1. Another potential source of your issue is a clogged condensation drain hose. The condensation drain hose removes moisture from the condensation created when the AC removes the humidity and directs it outside the home or to a floor drain. These drain hoses can become blocked by mold or algae growth, but this can be easily removed by a small screwdriver or something similar to clear the clog. If you find a clog high in the line, using suction from a wet/dry shop vac can often remove it.


  1. Sometimes, a refrigerant leak may be your problem. This chemical is crucial for the cooling process, and a leak can cause your unit not to blow cool air, run for longer periods, and cause damage to your compressor or a system shutdown. Call the Indoor Comfort Team for a guaranteed fix if you suspect a refrigerant leak.
  2. If you have air blowing out of your vents but your house is not cooling, a leak in the ductwork may be the cause.

    Ductwork leaks can lead to the cold air escaping before it reaches rooms, causing it to feel uncomfortably warm while other rooms feel colder.

    Finding the leak and fixing the ductwork can help with efficiency and performance. Call us, and we’d love to send out one of our knowledgeable techs to diagnose the issue –


  1. A faulty compressor, a broken capacitor, a malfunctioning contactor, and a faulty condenser fan motor are all parts of your outdoor unit that can malfunction and lead to the air from the vents not being cool in your home.


  2. Last but certainly not least, it may be time to look at replacing your AC unit due to age or insufficient capacity to cool your home. Call on the experts since 1979, Indoor Comfort Team, to take advantage of our amazing financing offer – just $69 a month for a new Trane system! We will discuss all your wants and needs to help you select a new, properly sized unit to keep you super cool all summer long.

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As we come to a close, remember that proper air conditioner maintenance is key to keeping your home comfortable and your AC blowing cool air, especially during these hot St. Louis summers.

If you’ve tried our tips and your AC still isn’t blowing cool air, don’t hesitate to reach out to the Indoor Comfort Team. Our team of experts is here to help you stay cool and comfortable all summer long. Don’t sweat it – we’ve got your back! Our phones are answered 24/7 – give us a call today (314)230-9542.

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Contact us today!

Indoor Comfort Team has been a trusted name in the greater St. Louis area since 1979. Whether you live on the Missouri side of the river or in Illinois, our skilled and licensed HVAC technicians are ready to deliver the services you need.

We provide complete heating and cooling installation and repair as well as water heater and indoor air quality services.

Need a repair today? Call (314) 230-9542 or (618) 688-0707.

Whether you need repair, maintenance, or new installation of your furnace or air conditioner, contact us today to let us get our comfort specialists right to work on your home or business.

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