Why Your AC is Running but Not Cooling in the Houston Heat (And What to Do)
It is the middle of the Texas summer, and your air conditioner has been running non-stop all afternoon. But when you walk inside and hold your hand up to the air vent, the air coming out is completely lukewarm.
This is a terrible feeling for any homeowner in the Houston area. When your AC is running but not actually lowering the temperature, it is easy to assume the worst and brace yourself for a massive replacement bill. However, as someone who has spent over 10 years repairing HVAC systems in New Caney, Kingwood, and Porter, I can tell you that this issue is often caused by a few common, fixable problems.
Before you panic and call a high-pressure salesman, here are the top four reasons your AC is running but not cooling, along with what you can do about it today.
1. A Severely Clogged Air Filter
It sounds too simple to be the main culprit, but a dirty air filter is the number one reason I get called out to homes during the summer.
Your AC needs a steady flow of warm air from your house to run over the cooling coils. When your filter is packed with dust, pet hair, and dirt, it chokes the system. The AC will keep running, but it simply cannot push enough cold air through the vents to cool your home.
The Fix:
Go check your air filter right now. If you cannot see light through it, throw it away and slide a fresh one in. Check your filter every 30 days during the peak Texas summer.
2. A Frozen Evaporator Coil
If you opened your indoor unit right now, you might actually see a block of solid ice sitting on your evaporator coil.
This usually happens because of poor airflow (like the dirty filter mentioned above) or low refrigerant levels. When the warm air from your house cannot reach the coil, the condensation on the coil freezes solid. Once it is encased in ice, the AC will just blow warm air into your house.
The Fix:
Turn your thermostat from "Cool" to "Off" immediately, but leave the fan setting on "On." This will force uncooled air over the ice to help melt it. Do not try to scrape the ice off yourself, or you could puncture the delicate coils. Once it thaws, give us a call to find out why it froze in the first place.
3. A Dirty Outdoor Condenser Unit
Take a walk outside to your backyard and look at the big metal box sitting out there. That is your condenser, and its job is to release the heat that was absorbed from inside your house.
If the sides of that unit are caked in mud, grass clippings, or dog hair, the heat cannot escape. The compressor will keep running and running, but the system will not be able to actually cool your home.
The Fix:
Grab a garden hose and gently wash the dirt and debris off the outer fins. Make sure you leave at least two feet of clear space around the unit by trimming back any bushes or tall weeds.
4. A Refrigerant Leak
Air conditioners do not consume refrigerant like a car consumes gas. If your system is low on Freon or Puron, it means you have a leak somewhere in the lines. When the refrigerant drops below a certain level, your AC will run continuously but lose its ability to blow cold air.
The Fix:
This requires a professional. We need to locate the exact source of the leak, repair the copper line, and recharge the system with the exact right amount of refrigerant.
The TwinStar 'Fix-First' Difference
If you have checked your filter and washed your outdoor unit but your house is still hot, it is time to let a professional take a look.
At TwinStar Air Conditioning & Heating, we operate with a strict 'Fix-First' philosophy. My team and I will exhaust every repair option before we ever suggest putting in a new system. When you call us, you get the owner, not a middleman.
We proudly serve Porter, New Caney, Kingwood, Humble, Atascocita, Spring, The Woodlands, and North Houston.
- ✓Honest Diagnostics: We handle all HVAC repairs with honest diagnostics. We charge an $89 diagnostic fee to find the exact root of the problem, and that fee is credited directly toward your repair.
- ✓Always Available: Texas heat doesn't take weekends off, and neither do we. We offer same-day emergency AC repair available 7 days a week, from 07:00 to 22:00.
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