Your Step-by-Step Guide to Getting Cool Air Flowing Again
It’s the middle of summer, and your AC isn’t blowing cold air. Frustrating, right? You’re not alone—and the good news is, many causes behind this common issue are easy to identify and fix.
At AiRCO Mechanical, we’ve assisted hundreds of homeowners in Texas and other areas in restoring cool air and comfort with practical, quick solutions. Below, we identify the 7 most frequent reasons why your air conditioner won’t cool—and how to fix them.
✅ 1. Filthy Air Filters
The #1 cause of AC units losing their cooling ability is a clogged air filter. Dust and dirt restrict airflow, causing your system to work harder—and perform less.
How to Fix It:
- Switch off your AC unit.
- Locate the air filter (often behind the return vent or within the indoor unit).
- Take out and change or clean it as per the manufacturer’s guide.
Pro Tip: Replace filters every 1–3 months, particularly during heavy use.
✅ 2. Wrong Thermostat Settings
Occasionally the issue isn’t your AC at all—it’s the thermostat.
How to Fix It:
- Double-check that the thermostat is in “Cool” mode.
- Decrease the temperature below the present room temperature.
- Change the thermostat batteries if they are old or low.
If it still doesn’t work, your thermostat could be broken and need to be replaced.
✅ 3. Low Refrigerant Levels
Refrigerant keeps the air cool. If your unit is running low on refrigerant—because of a leak or heavy use—it won’t blow cold air.
How to Fix It:
- Check for indications such as ice forming on the coils or hissing.
- Call a qualified HVAC professional to recharge the refrigerant and fix leaks.
⚠️ Safety Note: Never handle refrigerant unless certified.
✅ 4. Icy Evaporator Coils
When coils within your indoor unit become frozen, your AC is not able to cool the air properly.
How to Fix It:
- Switch off your AC and allow it to completely thaw (this can take several hours).
- Replace dirty filters and remove any blockages which could hinder airflow.
If freezing continues to occur, it might be a refrigerant or airflow problem—call a technician.
✅ 5. Dirty or Clogged Condenser Unit
The condenser (outside your house) must be unobstructed to dissipate heat. If clogged with debris or leaves, it will not function well.
How to Repair It:
- Disconnect power to the AC.
- Clear any loose debris.
- Rinse the condenser fins carefully with a garden hose.
Pro Tip: Make sure to have at least 2 feet of clearance around the unit.
✅ 6. Electrical Problems
Faulty wiring or tripped circuit breakers may prevent your AC from working properly—even if it seems like it’s operating.
How to Repair It:
- Look for tripped switches in your circuit breaker box and reset them.
- Check for obvious signs of wear or broken wires.
For more complicated problems, call an electrician or HVAC technician.
✅ 7. Leaky or Damaged Ductwork
Even if your AC is functioning, cold air may be leaking out through holes or gaps in your duct system—before it even hits your vents.
How to Fix It:
- Check for gaps or disconnections in ductwork.
- Plug small leaks with duct tape or mastic sealant.
For more significant problems, arrange for professional duct sealing.
🛠️ Preventative Maintenance Tips
Maintain your system operating at its best year-round with these easy steps:
- Plan for annual HVAC tune-ups.
- Replace air filters periodically.
- Leave outdoor condenser units clean.
- Deal with refrigerant problems early to prevent expensive fixes.
📞 When to Call an HVAC Technician
Some AC issues are more than a DIY job. Call the experts when:
- Your AC is still not cooling after these repairs.
- You detect strange noises, odors, or water leaks.
- The unit is constantly cycling on and off without cooling effectively.
❄️ Get Cool Comfort Back—Fast
An AC that doesn’t blow cold air can be frustrating, particularly in the middle of sweltering summer. But more often than not, a few basic solutions are all it requires to get your system running again. If you’ve already done it all and the heat is still getting to you, our AiRCO Mechanical crew is only a phone call away.
We can assist you in getting your house back to the ideal temperature—hassle-free and dependably.
❓FAQs
Q1: Why won’t my AC cool my house?
A clogged filter, low refrigerant, frozen coils, or thermostat problems are the most frequent offenders. Attempt to replace the filter and check settings prior to requesting assistance.
Q2: Is low refrigerant hazardous for my AC?
Yes. Operating your system low on refrigerant can ruin the compressor and result in costly repairs.
Q3: Why is my AC freezing up continuously?
Constricted airflow (usually from dirty filters) or low refrigerant may make the coils freeze.
Q4: Can I clean the condenser unit myself?
Yes, but first, turn off the power and use a garden hose lightly to spray out dirt and debris.
Q5: What’s the average cost of AC repair?
Simple repairs usually run from $100 to $500, depending on the problem and parts required.