7 Reasons and Causes to Investigate
When your air conditioner isn’t blowing cold air like it’s supposed to, that can be one of the most frustrating things as a homeowner. Not only do you and your family feel uncomfortable indoors, but it can also feel like a waste of energy and money.
Fortunately, an AC system blowing warm or hot air doesn’t always have to be that big of a problem. With some inspection and troubleshooting, you might be able to fix the problem yourself.
With 90+ years of experience, the experts at National Heating and Air Conditioning know a lot about air conditioning. In this blog, we’ll walk you through the seven most common reasons why your AC is on the fritz.
7 Potential Reasons Why Your AC Isn’t Blowing Cool Air
If your air conditioning is blowing warm air, these are the common reasons why:
- Fan setting
- Coolant leak
- Dirty filter
- Blocked unit
- Electrical issue
- Frozen evaporator coil
- Broken wires
#1: Fan Setting
If your thermostat is set to “on” instead of “auto,” the fan will run continuously, even when the system isn’t cooling. That means the air blowing from your vents may be unconditioned and feel warm or lukewarm.
Troubleshooting tip: Check your thermostat. If the fan is set to “on,” change it to “auto.” This ensures the fan only runs when the system is actively cooling the air.
#2: Coolant Leak
Your air conditioner likely relies on coolant or refrigerant to absorb heat from your home’s air. If there’s a coolant leak, the system can’t cool properly, and it ends up blowing warm air instead. In addition to distributing warm air, a coolant leak can cause long-term damage to your compressor if not resolved quickly.
Troubleshooting tip: Listen for a hissing or gurgling noise around your outdoor unit, and check for ice buildup on the refrigerant lines. If you notice either, turn off your system and call a professional for help.
#3: Dirty Air Filter
A dirty air filter limits the system’s ability to cycle air through the evaporator coils and cool it. As a result, the air may come out warm.
Troubleshooting tip: Turn off your HVAC system, remove the air filter, and inspect it for dust and debris. A good trick is to hold the filter up to the light, and if little or no light passes through, that’s a sure sign it’s time to replace it. Aim to check your filter monthly and replace it about every two months, depending on use.
#4: Blocked Unit
If your outdoor AC unit is covered by leaves, weeds, or other debris, it won’t be able to do its job efficiently. Specifically, a blocked unit can prevent the outdoor condenser coil from releasing heat (which can cause a system to blow warm air).
Troubleshooting tip: Inspect the area around your outdoor condenser. Remove any excessive debris and try to ensure there’s about 2 feet of clearance on all sides. You’d be surprised how a simple cleanup can produce a big difference in AC performance.
#5: Electrical Issue
Sometimes, your outdoor unit might have a power or electrical issue. Even if the outdoor condenser doesn’t have power, your indoor unit (aka air handler) will still circulate air. Without the cooling process occurring with the condenser, your AC system will blow warm air.
Troubleshooting tip: Stand near your outdoor compressor and listen for its normal hum or fan spinning. If it’s silent, check your electrical panel for a tripped breaker or blown fuse. Reset the system, but if it continues to occur, call an HVAC technician.
#6: Frozen Evaporator Coil
Your evaporator coil can also freeze up due to restricted airflow or low coolant levels. When this happens, the coil can’t absorb heat, so the system defaults to blowing warm air anyway.
Troubleshooting tip: To help thaw the coil, turn off the AC and run the fan. If it continues to freeze, call a professional for help.
#7: Broken Wires
Wiring problems are especially common for older HVAC systems. A single loose or broken wire can prevent your AC from cooling while the fan continues to run. These issues can occur after decades of use, someone bumping into the unit, or a failed DIY maintenance attempt.
Troubleshooting tip: In addition to noticing your AC blowing warm air, you can detect an internal electrical issue if the system turns on and off unpredictably. However, due to the complexity and safety, resolving a wiring or electrical issue is best left to a professional HVAC technician.
Get an AC Inspection in Cincinnati, OH!
If you’ve tried some of these troubleshooting tips with no success or you’d rather trust a professional anyway, let National Heating and Air Conditioning help. With 24/7 emergency AC service and a 100% satisfaction guarantee, our NATE-certified technicians can swiftly resolve the issue.
You don’t need to ignore an AC issue. Contact National today for fast, effective service in Blue Ash or Cincinnati.
