AC Troubleshooting
AC Making Noise — What It Means in Maine
Air conditioners should run with a steady hum. Banging, rattling, squealing, or grinding sounds indicate something needs attention. RG Mechanical diagnoses AC noise issues throughout Central Maine before they turn into expensive failures.
What to Expect
Banging or clanking: loose or broken fan blade — turn off immediately
Squealing: fan motor bearing failure or worn belt
Rattling: debris in the outdoor unit or loose panels
Clicking: normal at startup/shutdown, continuous clicking indicates a control issue
Hissing or bubbling: refrigerant leak
Humming but not starting: failed capacitor or contactor
Frequently Asked Questions
My AC started making a loud banging noise. What do I do?
Turn the unit off immediately — a loose or broken fan blade can destroy the outdoor unit. Call us for emergency service.
What causes AC squealing?
Fan motor bearing failure is the most common cause. Some older units have a belt drive — a squealing belt needs adjustment or replacement.
My AC sounds like it's hissing. Is that a refrigerant leak?
Possibly. Hissing or a bubbling sound near the refrigerant lines or outdoor unit often indicates a refrigerant leak. Turn off the unit and call us for diagnosis.
My AC hums but won't start. What's wrong?
A humming compressor or fan motor that won't start usually indicates a failed capacitor — the part that gives the motor the extra boost it needs to start. Capacitor replacement is a common, affordable repair.
Ready to get started?
Call us or request a project estimate. Contact RG Mechanical to confirm service availability for your community.
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