In the greater Austin area, we’re no strangers to temperatures climbing past 90, 95, and even 100 degrees. That’s just part of life here, but it doesn’t make it any less miserable when your house won’t cool down past a certain degree. Does your air conditioner stop cooling when it goes above 95? Sometimes that can be normal—though not always. In this blog, we’ll talk about why it happens, what you can do to help your system on extremely hot days, and when it’s time to schedule an AC repair.
AC Not Cooling in Hot Weather? Here’s What Might Be Happening
We get asked “Why is my AC running but not cooling?” quite a bit once summer really kicks in. First, let’s clear a couple of things up. An air conditioner not cooling house issue can sometimes be related to the weather itself or how low the thermostat is set. An AC blowing warm air, though, is usually more connected to a problem inside the system. Either way, it helps to understand why you may have an AC not cooling in hot weather before things get worse.
Your System May Be Working as Hard as It Can
A lot of homeowners think something is wrong the second the house creeps above the thermostat setting, but during extreme heat, even a healthy air conditioning system can struggle to keep up. Most central air conditioners can only remove so much heat at a time, especially once high temperatures climb into the triple digits.
That’s why some homes settle in the upper 70s during the hottest part of the afternoon even with the AC system running nonstop. If the system is still producing cool air and maintaining fairly stable temperatures, it may simply be dealing with unusually high heat outdoors.
Your Thermostat May Be Set Too Low
When summer heat gets intense, it’s tempting to lower the thermostat way down hoping the house cools faster. But central AC systems don’t cool more aggressively just because the thermostat says 68 instead of 72. The AC unit still removes heat from indoor air at the same rate. Lowering the setting too much can cause the system to run continuously for hours, creating more energy use and extra wear on the HVAC system without improving comfort very much.
Airflow Problems Can Choke the System
Dirty air filters, blocked vents, and restricted air ducts can all affect how well your cooling system performs during high heat. If the system can’t move enough air, it becomes much harder to circulate air throughout the home and maintain comfortable temperatures. Dirty coils on the outdoor condenser coil can create similar problems by trapping heat inside the system. Restricted airflow creates increased strain across the whole AC system and can eventually lead to frozen coils or weak airflow from the vents.
Low or Leaking Refrigerant Makes Cooling Much Harder
Your AC system depends on proper refrigerant levels to cool effectively. Refrigerant enters the evaporator coil and absorbs heat before carrying it outside where the outdoor unit releases it. If there’s a refrigerant leak, that entire process becomes much less effective. You may notice weaker cold air, longer cooling cycles, or only warm air coming from the vents during the hottest part of the day. Letting low refrigerant continue can eventually damage the compressor.
The Outdoor Unit May Be Overheating
Your outdoor condenser unit has one main job: to remove heat from the house and release it outdoors. During high heat, that job gets much harder, especially if the condenser fan isn’t moving enough air or the outdoor unit is coated in dirt and debris. Dirty coils can trap heat inside the condenser unit and reduce overall AC performance. As outside air temperatures climb, the system may start falling behind because it physically can’t remove heat fast enough anymore.
Worn Parts Start Showing Their Age
Sometimes, extremely hot days expose problems that were already developing inside the HVAC system. Weak fan motors, a struggling blower motor, aging electrical parts, or a worn compressor may still work during milder weather but begin failing once the system is under heavy demand. Heat creates extra stress on every moving part inside the AC unit. If your system suddenly struggles every afternoon once temperatures spike, there’s a good chance an underlying issue was already there.
How to Troubleshoot an AC Blowing Warm Air or Not Cooling
If you feel comfortable, there are a few things you can try before scheduling service for an AC not cooling in hot weather. Sometimes, small airflow or thermostat problems can make a system struggle more during high heat. Here are a few things that our air conditioning experts recommend:
- Double-check your thermostat settings and make sure the system is in cooling mode
- Make sure the set temperature is at least a few degrees below the indoor temperature
- Replace a dirty filter with a clean filter to help restore proper airflow
- Check indoor vents to make sure furniture or rugs aren’t blocking airflow
- Clear grass, leaves, and other debris away from the outdoor unit
However, our technicians don’t want you:
- Opening sealed electrical panels or touching wiring
- Spraying water deep into the system or attempting coil cleaning yourself
- Trying to add refrigerant to the system
- Chipping or scraping ice off frozen components
- Continuing to run the system nonstop if it’s only blowing hot air
There’s nothing wrong with trying a few safe troubleshooting steps first, but most cooling problems go beyond what homeowners should handle themselves. Even if things improve after changing the filter or adjusting settings, it’s still a good idea to schedule AC repair and have the system checked out professionally.
In the meantime, try to stay cool by limiting heat-producing appliances, keeping blinds closed, and using ceiling fans (or desk fans or floor fans) to help move air around the house.
Hot House? Call Austin Air Conditioning to Cool Things Down
An AC not cooling in hot weather is probably the number one call we get during summer because when you lose air conditioning in Central Texas, boy, does the house get miserable fast. If you’re dealing with that right now and you’ve tried a little DIY troubleshooting—or even if you haven’t—we’re always here to help with a fast AC repair. We offer emergency services, and our experienced technicians come out quickly to inspect your system, figure out what’s going on, and get you headed toward a solution.
We’ve been fixing air conditioners here since 1990, so we know how bad this heat can get and what it does to AC systems. For the AC repair Austin area homeowners know and trust, contact Austin Air Conditioning today.
