Why Is My Air Conditioner Not Cooling?

It’s hot outside and it’s just as hot in your house! You’ve adjusted the temperature on your thermostat, checked to make sure all the vents are open yet there is no cold air coming out. Something is definitely wrong. We’ve compiled the top 10 most common reasons why your air conditioner is not cooling your home.

  • Dirty Filter. The cool air needs to be able to circulate freely through your home. If the filter is dirty or clogged up, the flow can be significantly reduced and cause the air to get backed up. Not only does this make for poor cooling, but it can also cause a lot of harm to your system itself. A good way to see if your filter is dirty is to hold it up to the light. If limited light comes through it’s time to change it, or if you have a washable filter, clean it. If at all in question change it!
  • Drain Back-Up. Just like your unit’s filter, your drain line can become clogged with all kinds of things. Once it’s stopped up, there is nowhere for the water that builds up to drain out. This can cause damage to the unit and anything around the drain area.
  • Thermostat. If the thermostat seems to be set correctly and you are still not cooling, there is a chance that it has malfunctioned. If this is the case, it may be time for a new one.
  • Tripped Breaker. Sometimes the cause may be as simple as a tripped breaker. Take a look in the breaker box and see if everything is on. If you find that the breaker has tripped, turn it back on. You may however want to call an electrician anyway to see what may have caused the shut-off in the first place.
  • Leaking or Low Refrigerant. If there is a refrigerant leak, the unit will not perform as it should. Same thing if you are low on refrigerant. A great way to avoid this is to schedule an annual inspection of your HVAC system to make sure everything is in tip-top shape.
  • Faulty Compressor. The compressor is what regulates the refrigerant within the unit. It’s pretty technical stuff but think of it as the heart of your air conditioning system. Without a working compressor, nothing is pumping to where it should be.
  • Clogged Condenser. You must have proper airflow for your air conditioner to work properly. Check your outdoor unit to make sure there are no blockages and enough space (2-3 feet) between it and structures or plants. Trees should not hang less than 5 feet from the top of the unit.
  • Corroded / Clogged Evaporator Coils. Heat is absorbed by the evaporator coils and then sends cool air back into your home via the air ducts. The coils can fail, become corroded or become clogged and, as a result, will stop doing their job.
  • Leaky Ducts. Many things can cause damage to your ducts including rodents and debris. If there are leaks in the ducts, the cold air can leak out before it makes it out of the vents and into your home. It could also be pulling hot air and dust/debris into your home from attic.
  • Worn Connectors or Contacts. There are a lot of moving electrical parts that keep your A/C functioning properly. Over time, one or more of those components may become worn out and stop working. They will need to be replaced to get you feeling cool again.


If you’re feeling the heat indoors this summer Texas Ace Heating & Air knows how to get the cold air flowing again. Call us at 817-240-6701 or contact us online and we will get you back to your comfort zone in no time!