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AC Making Loud or Strange Noises
in Lewisville, TX
AC units in Lewisville run hard — sometimes 10 to 12 hours a day from May through September. That kind of use wears parts down faster than mild climates. A new noise from your unit is almost always telling you something is wrong, not working itself out.
Quick Answer
Strange noises from your AC usually mean something is loose, worn out, or broken inside the unit. In Lewisville, units that have been through several years of hard summer use are the most common source of these calls. Some noises mean shut it off right now. Call (361) 401-8806 and describe what you're hearing so we know how fast to move.
Telltale Signs
Warning Signs to Watch For
- A banging or clanking sound from the outdoor unit when it starts
- A high-pitched squealing noise from the indoor air handler
- A rattling sound that shows up when the fan is running
- A hissing or bubbling sound near the refrigerant lines
- A grinding noise that gets worse the longer the unit runs
- Clicking that doesn't stop after the unit starts up
Root Causes
What Causes AC Making Loud or Strange Noises?
Loose or Broken Fan Blade
The outdoor condenser unit has a large fan that pulls air across the coils. If a blade cracks or comes loose — which happens more often on units more than 8 years old sitting through years of Lewisville heat and hail — it bangs against the housing every rotation. Running it that way can destroy the fan motor.
The Fix
Fan Blade Replacement
A technician shuts the power off, removes the fan assembly, and replaces the damaged blade. The motor gets checked at the same time since a bad blade often puts extra load on it.
Worn Blower Motor Bearings
The blower motor inside your air handler moves air through your home. Its bearings wear down over time, and in Lewisville homes where the system runs nearly year-round, that wear happens faster than the manufacturer's estimates assume. Worn bearings make a grinding or squealing sound and will eventually seize up.
The Fix
Blower Motor Replacement
Replacing the blower motor stops the noise and prevents a full system shutdown. A technician also checks the blower wheel for buildup, since a dirty wheel puts more stress on the new motor.
Refrigerant Leak Hissing
A hissing or bubbling sound near the refrigerant lines usually means refrigerant is escaping through a crack or bad fitting. This is common on older copper line sets that have gone through many years of expansion and contraction in the Lewisville heat. A hissing leak means refrigerant is actively escaping and the system needs to be shut off.
The Fix
Leak Repair and Line Set Inspection
The technician finds the leak point, repairs or replaces that section, and checks the rest of the line set for soft spots or corrosion. The system is then recharged to the correct level.
Self-Diagnosis
Which Cause Applies to You?
Check the signs you're observing to narrow down the likely root cause before your inspection.
| What You're Seeing | Loose or Broken Fan Blade | Worn Blower Motor Bearings | Refrigerant Leak Hissing |
|---|---|---|---|
| Banging or clanking from outdoor unit at startup | |||
| Grinding or squealing from the indoor air handler | |||
| Hissing sound near refrigerant lines | |||
| Rattling that stops when the outdoor fan slows down | |||
| Noise gets louder the longer the unit runs | |||
| AC stops cooling at the same time noise starts |
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