Low voltage transformer for heating or air conditioning (C) Daniel FriedmanElectrical System Noise Sources
Find & fix noises traced to building electrical components, wiring, devices

  • ELECTRICAL SYSTEM NOISES - CONTENTS: Building & house electrrcal noises, sources of building noises traced to the electrical system: appliances, electrical lights, wiring, switches, circuit breakers: buzzes, hums, and vibrations. Watch out: some electrical system noises indicate unsafe conditions.
  • POST a QUESTION or READ FAQs about diagnosing the source and finding the cure for noises or sounds in or around buildings and their systems
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Building noise traced to electrical system components, fixtures, devices, transformers, relays, or wiring.

How to track down and fix building sounds originating in electrical system components or devices.

We also discuss methods of sound or noise control in buildings during construction or as a building retrofit.

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Electrical Equipment or Electrical System Noises in buildings: diagnosis & cure

Uninterruptible power supply (C) Daniel FriedmanWatch out: Electrical System Noises can be signs of dangerous conditions: buzzing circuit breakers or fixtures may indicate that an electrical circuit is short circuiting or that a circuit breaker is not tripping when it should.

The risk is fire or electrical shock. If a circuit is acting strangely with flickering lights, noises, or odors, turn it off at the main electrical panel and call a licensed electrician promptly.

If you are unable to safely turn off an electrical circuit for any reason, get people out of the building and call your fire department or emergency services. See

  • Air conditioner compressor motors or fan motors that are damaged, unable to start, or may be suffering from low voltage or a bad start capacitor may hum without starting.

    Watch out: Shut off elecrical motors that hum without starting to avoid overheating, further damage, and a possible electrical fire.

    See AIR CONDITIONING & HEAT PUMP NOISES for a list of sounds coming from those systems

    For heat pump or air conditioner compressor motors that hum see HUMMING sounds from A/C or Heat Pump system

  • ALUMINUM WIRING HAZARDS - flickering lights, circuits that do not turn off or on, hissing crackling sounds, burning plastic odors.

    Watch out: turn off electrical circuits that are flickering or making noise and obtain help from a licensed electrician
  • Buzzing sounds (also crackling) at electrical components anywhere, including compressor relay switches, electrical connections at any component, and quite seriously, at circuit breakers can be an indication of arcing and an electrical problem needing prompt attention.

    Watch out: Turn off such circuits immediately and contact a professional electrician or service technician.


  • ELECTRIC METERS & METER BASES of older designs sporting a rotating metal disc may produce a whirring sound when the meter is spinning. At a Poughkeepsie New York home we asked the local electric meter reader about the noisy meter on a house. He gave the meter a solid smack! The noise stopped. For a time. We don't recommend this repair approach, though indeed sometimes mechanically disturbing a noisy part is diagnostic.
  • Electronic equipment noises - clicks (typically relays), ticks, and whirs (typically fan noises), and occasional snap-click sounds (hard drive or disk accessing) are noticed by people with acute hearing.

    Our photo (above left) shows a backup computer equipment power supply that contains a battery, switching equipment, and electric power conditioning circuitry. We expected it to be silent, but in fact in a quiet room one can hear a periodic clicking from an internal relay in the device.
  • Electric Motor noises - include normal operating hums and louder noises when a motor bearing is failing, a pump is runnign dry, or the motor shaft is binding.
    See ELECTRIC MOTOR NOISE DIAGNOSIS for a list of diagnostic checks for noisy electric motors.
  • ELECTRICAL SYSTEM INSPECTION for home buyers provides guidance in identifying and fixing electrical hazards in homes: aluminum wiring, Federal Pacific FPE Stab-Lok panels, mis-wired circuits, fire and shock hazards
  • FEDERAL PACIFIC FPE HAZARDS - flickering lights, circuits that do not turn off or on, hissing crackling sounds, burning plastic odors
  • FLICKERING LIGHT DIAGNOSIS - causes of flickering or dimming lights
  • HEAT, ELECTRIC - clicks or creaks as an electric baseboard heats up are normal. But hissing, buzzing, crackling, snapping may be an electrical short and are dangerous. Heating system noises involving electrical components may be traced to motors, relays, switches, transformers and wiring.
  • LOW VOLTAGE BUILDING WIRING - may include low humming noises at failing voltage transformers
  • OIL BURNER NOISE SMOKE ODORS describes other sources of noisy oil burner motors & assemblies.
  • PUSHMATIC - BULLDOG PANELS - flickering lights, circuits that do not turn off or on, hissing crackling sounds, burning plastic odors
  • RUST in ELECTRICAL PANELS - flickering lights, circuits that do not turn off or on, hissing crackling sounds, burning plastic odors
  • SQUARE-D RECALLS - flickering lights, circuits that do not turn off or on, hissing crackling sounds, burning plastic odors
  • Transformer buzzing: low voltage transformers power building components such as doorbells and heating or air conditioning controls. A failing transformer may buzz.

  • ZINSCO / SYLVANIA HAZARDS - flickering lights, circuits that do not turn off or on, hissing crackling sounds, burning plastic odors


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