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I Keep Lowering the Temperature, but My AC Won’t Make the Home Cool Enough!

Woman and a Fan

When I get too hot, I pant. It’s a simple trick we dogs have done for centuries, and it works pretty well—even with the fur coat. When people get hot, they turn on their air conditioning systems by adjusting the thermostat to a lower temperature.

But what if that didn’t work? The air conditioner is running, but the cool air coming from the vents isn’t overcoming the heat the way it’s supposed to. You lower the thermostat more, but nothing helps. The house is still too hot and stuffy. What’s happening?

First Things First …

Before I look into the possible reasons your AC can’t keep up with the warm weather, I need to bring your attention to an important fact about the thermostat: lowering the thermostat doesn’t give you more cooling! All that happens is the air conditioner will run for longer as it attempts to reach the lower setting. If the air conditioner is already struggling to cool the house, it won’t be able to reach an even lower temperature—it will just stay on, wasting power without making a difference in the household climate. Leave the thermostat at a higher setting (I recommend 78°F) until the AC’s problem is addressed.

Now … Why This Might Be Happening

Here are a few of the more common reasons for an AC that’s losing its power to keep you cool.

  • Clogged filter: Always check the filter on the HVAC system first when you’ve got cooling problems. A clogged filter is often at the root of many performance issues.
  • Blocked condenser: The condenser (the outdoor unit) of an AC needs to be clear on all sides so it can exhaust heat. If the condenser is blocked or excessively dirty, the air conditioner will not be able to cool down its refrigerant low enough.
  • Thermostat malfunction: Yes, I just mentioned not to fool with the thermostat. The thermostat could be what’s wrong, however. If it’s miscalibrated, the thermostat might be forcing the AC to shut off early. You will need a technician to handle repairing it, so what I said about not tampering with the thermostat still stands.
  • Loss of refrigerant: Leaks along the refrigerant lines are serious problems. When the AC has less refrigerant than normal, it will start losing its cooling power—and worse troubles are ahead, such as a potentially ruined compressor. You want this fixed ASAP.
  • Over the hill AC: If the air conditioner is more than 15 years in service, losing its cooling power may be a sign that it’s time to have it replaced. Repairs might be able to restore it, but in most cases, it’s more cost-effective to take the money for the repairs and invest in a new start with the air conditioning.

You can trust our experts for any air conditioning repair in Knoxville, TN you may need. We’ll also give you honest answers about whether it’s time to retire an old air conditioner and replace it with one of the great Onyx models we carry.

Stay cool,