Why is your central air conditioner not blowing cold air? When the temperatures rise, you rely on your Charleston, SC, HVAC system to provide refreshing cool air in your home and business. You have set the thermostat, and you can hear the blower fan running, but when you lift your hand to a vent register, the air is warm or neutral at best. This will not do. The hotter it gets outside, the less patience you have for a lukewarm performance from your air conditioning unit.
What’s puzzling is that your AC appears to be running; it’s just not producing any cold. Why would an air conditioner not create cold air? At Smoak’s Comfort Control, we can help you find the reason and the solution quickly.
Here are the five most likely reasons why your AC might be blowing without creating cold air and what you can do about each possibility.
Reason 1: Dust Buildup on the Coils
The first and most likely cause is dust buildup on the coils. Inside your AC unit, the refrigerant flows through the coils while air flows over them. This makes the air cold and warms the coils to facilitate the refrigerant cycle. However, if too much dust gets into your HVAC unit, it will form an insulating blanket over the coils, trapping cold on them and preventing air from becoming cold by exposure. This is especially likely if you don’t change your air filters frequently.
Dust buildup can even lead to the “icebox” AC problem, where an AC builds up ice due to the trapped cold while still functioning inefficiently at spreading cold through the house.
What to Try: Let it Thaw.
If your AC sometimes produces cold air and stops, you can try letting it thaw out by giving the AC a temporary break. Waiting 30 minutes to 2 hours can allow your AC to thaw so you can resume creating cold air. However, this is only a quick solution, as dust on your coils still causes these freeze-ups.
Repair Solution: Have Your AC Cleaned and Maintained
Dust buildup inside your AC is the reason to call an HVAC technician. They will open the unit, clean away the dust, and then perform a full inspection. After this process, your AC should start producing cold air when the fan blows again.
How to Prevent: Change the Filters Often
We recommend changing your air filters every 1 – 3 months or whenever needed to prevent dust from getting through to build up on the coils.
Reason 2: Thermostat Error
The second possibility is an issue with your thermostat. If your AC is running but not blowing cold air, the thermostat may have failed to tell the AC unit to get started. Your thermostat can trigger the blower fan (that’s what the “fan only” setting is), but without the AC pitching in, the air will be room temperature to warm during the summer.
What to Try: Reset the Thermostat
Thermostats are tricky, but you can get the AC back on simply by fiddling with the settings. Try turning your thermostat off and back on again, switching from heat to fan and back to cold, or changing the temperature the thermostat is trying to reach. If any of these things engage the AC and you start getting cold air again, consider having your thermostat recalibrated at your next HVAC maintenance visit or schedule a thermostat repair.
What to Try: Replace the Thermostat Batteries
You can also check and see if your thermostat needs fresh batteries. Some thermostats pull off from the wall and have a battery compartment inside instead of being wired into the house. If yours does, pop in a few fresh batteries, reset the settings, and see if that works.
What to Try: Test the Thermostat Sensors
Does your thermostat think it’s much colder in the house than it is? Depending on the thermostat’s location and possibly dirty sensors, it might not trigger the AC to fire cold air.
Solution: Have Your Thermostat Fixed or Replaced
Of course, if your experiments don’t work and your thermostat does not need new batteries, the best answer is to call an AC repair technician to look and possibly replace it with a new thermostat.
Reason 3: The Condenser is Out
The condenser is the outdoor unit crucial to the refrigerant system of your AC. Because the system is outside, it can become clogged with things like leaves, grass, other debris, or a nearby plant, which can interfere with the cooling cycle.
What to Try: Clear Leaves & Debris from the Outside of the Unit
Naturally, the first step is to remove debris from your outside AC unit. Sweep away leaves and try to remove any foliage inside the unit through the vents.
Repair Solution: Have Your Condenser Maintained or Repaired
If you can’t clear everything or find signs of damage, call an HVAC repair service to open the system, clean the unit, and give your system a tune-up.
How to Prevent: Protect the Condenser from Debris
You can prevent issues with your compressor by landscaping to prevent it from getting filled with leaves of grown-through nearby plants. A small hutch, fencing, or gravel-covered space around the unit can help.
Reason 4: Refrigerant Leak
Your HVAC refrigerant is a closed system that cycles for years, but if it springs into a leak, you have a significant problem. Not only are refrigerants dangerous, but your AC won’t be able to create cold without it, so that the air conditioner will be running but not cooling.
What to Try: Nothing
Refrigerant leaks are beyond the DIY level, repairing unusual and hazardous materials, careful handling, and access to the AC’s most enclosed system.
Repair Solution: Have Your HVAC Repaired and Refilled
If you suspect you have a refrigerant leak based on icy lines or not enough cold blowing from your vents, call for repairs as soon as possible.
Reason 5: Your Ductwork is Leaking
Lastly, there’s a chance that your air conditioner is not blowing cold air even though the thermostat is on because it’s escaping through your air ducts. You can sometimes tell if you have irregular or weak air pressure from your vents. If there’s a gap or hole in your ductwork, all your cold air might flow into the hot, uninsulated spaces between your walls or outdoors.
What to Try: Nothing
Ductwork is oftentimes found in an attic, so you’ll need a professional to handle this matter.
Repair Solution: Duct Inspection and Repair
Schedule an air duct repair. Our HVAC technicians will know what to do and have special tools and equipment to identify leaks and get them repaired, even in hard-to-reach areas.
Restoring the Cold to Your Air Vents
If your home’s AC isn’t blowing cold air, we have the solutions. If a bit of DIY troubleshooting doesn’t resolve the issue, or it comes back regularly, Smoak’s Comfort Control is here to help. Our highly-trained technicians can perform a wide range of HVAC services, including a full inspection of your HVAC system to find the problem and provide the proper cleaning, repairs, replacement, and maintenance you need to get cold air flowing through your home again.
Call us today or contact us online to schedule an appointment.