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Flickering Lights & Electrical Power Loss
Diagnose & fix flickering, dimming lights or lost electricity

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A diagnostic catalog of the causes & cures of of dimming light fixtures or flickering lights & power losses.

How to diagnose the causes of flickering or dimming lights at or in buildings.

This article gives simple diagnostic steps that a homeowner can do to determine the type of electrical system problem that is causing flickering or dimming lights or intermittent loss of electrical power. We list the common causes of these problems and suggest what to do about them.

Watch out:  flickering or dimming lights often indicates a dangerous condition. Switch off the bad acting appliance or circuit and ask for help from a licensed electrician.

We also provide an ARTICLE INDEX for this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Dimming or Flickering Lights Indicate Electrical Hazards in Buildings: What to Do

Watch out: flickering or dimming lights at a building may be more than an inconvenience.

While some causes of flickering lights may be normal and harmless, such as flickering in certain types of light bulbs, many others indicate a dangerous condition, risking fire, shock, injury or worse.

The safest approach is to turn off electrical circuits or components that are causing flickering or dimming or acting strangely in any way.

If you cannot safely access your electrical panel to turn off dangerous circuits or components, leave the building and call your local emergency services.

At FLOOD & DISASTER BUILDING DAMAGE REPAIR PROCEDURES we list emergency numbers for various countries from Australia (000) to the U.K. (112). In Canada or the U.S. call 911. In Mexico call 066.

[Click to enlarge any image]

Photo: a fluorescent light fixture may be the only electrical device that is flickering, for any of several reasons we will explain below. Other causes of flickering lights are very dangerous.

How to Diagnose Dimming or Flickering Lights at Buildings

In diagnosing the cause of flickering or dimming lights at a building the following diagnostic questions can help narrow down the cause of the trouble.

1. Is the dimming light or power loss problem happening in just your building or do neighbors see the same problem at exactly the same time?

   If your neighbors are seeing flickering or dimming lights too, chances are the problem is in the electrical supply network or possibly at local electrical wiring in your neighborhood or its power transformer. If your neighborhood frequently loses electrical power

   see BACKUP ELECTRICAL GENERATORS

2. Is the dimming problem or power loss showing up in the whole building or just parts of it? If all lights in the building dim, flicker, or if all power is lost, then the problem is probably in the electrical panel or at the service entry cabling to your building.

   The electrician will look for a problem in the electrical panel, at the main breaker, at the service entry wiring connections or at the SEC wiring itself, including the two hot wires and the service neutral wire. But see the exception in step 4 below.

   If the dimming, flickering, or lost power occurs in multiple circuits in the building the problem could still be in the electrical panel itself, or in the service entry wiring to the building.

   See examples of electric meter failures

   at ELECTRIC METERS & METER BASES

   Also see ELECTRICAL SERVICE ENTRY WIRING - home

3. Is the dimming or flickering light problem or power loss associated with circuits in just half of the electrical panel? Depending on electrical panel layout, damage to one panel bus can cause failures or odd behaviour on electrical circuits connected to that panel bus.

   See the power loss traced to electric meter failures

   at ELECTRIC METER ARC BURN POWER LOSS

   Also see ELECTRICAL SERVICE ENTRY WIRING - home

4. Is the dimming light problem or power loss associated with the operation of a single, specific appliance or motor? This is an exception to the case described in step 2 in that all lights may dim when there is a developing failure in a single major appliance such as an air conditioner compressor motor.

   Such motors can draw very high amps (current) for just a brief moment when the motor is starting.

   If the current surge is very brief, no circuit breaker may trip but the load may be sufficient to dim all of the incandescent lights that are on or all of fixtures in just part of the building, depending on how the appliance circuit is wired in the electrical panel. (Fluorescent lights probably won't dim).

   If the problem never occurs when the circuit to that appliance has been turned off you've probably found the trouble.

   If the problem is traced to a specific appliance but is intermittent, other variations in conditions such as temperature, humidity, vibration, or moving around of a loose wire may explain that inconsistency.

   See also ELECTRIC MOTOR DIAGNOSTIC GUIDE - home

5. Is the dimming or flickering light or power loss showing up on just a single circuit? In this case we suspect a faulty circuit breaker or bad connection in the circuit.

   Some circuit breaker brands are particularly prone to failure such as FPE Stab-Lok and Zinsco-Sylvania. In this case the problem may ultimately show up on additional circuits in the same building, depending on building age and circuit usage levels and other conditions.

   See ELECTRICITY TURN ON AFTER BREAKER TRIP

   See CIRCUIT BREAKER FAILURE RATES

   Also see these examples of problematic electrical panels

• FEDERAL PACIFIC FPE HAZARDS
• MURRAY CIRCUIT BREAKER HAZARDS
• MURRAY SIEMENS Recall
• PUSHMATIC - BULLDOG PANELS
• SIEMENS MURRAY Recall
• SPLIT BUS ELECTRICAL PANEL HAZARDS
• SQUARE-D AFCI RECALL 2004
• SQUARE-D COUNTERFEIT BREAKER RECALL
• ZINSCO SYLVANIA ELECTRICAL PANELS
6. Is the dimming or flickering light or power loss showing up just at some fixtures or appliances?

   A likely cause of this problem is a failing appliance or motor that is drawing abnormally high current as we cited in step 4.

   But sometimes the problem may occur only at lights or appliances plugged in electrically "downstream" from a specific electrical circuit, or at lights operated by a specific switch. In this case we suspect the trouble is not the appliance itself but in connectors within the receptacle or switch or immediately "upstream" (electrically) from it.

   Some receptacle and switch types such as older push-in back-wired devices are more likely to have loose or failing electrical connectors with age and usage.

   Try plugging in the light fixture or appliance at a different location on a different electrical circuit in the home. If the bad behavior continues then the trouble is in the light or appliance itself.

7. Is the flickering light showing up at just one light fixture? Look for loose wiring or an overheating fixture.

8. Is the flickering light found in a fluorescent fixture?

   If so, while checking for a loose wire or poor fluorescent bulb connection is important, the most common causes of flickering fluorescent light fixtures are

• A bad fluorescent light bulb - take a bulb from a fixture working properly and test it in the flickering fixture; also look for black or other discoloration in the flickering bulb. Replace it.
• A bad starter in the fixture
• A bad ballast in the fixture

In the photo above I am showing the original data tag for this Fox Co. fluorescent fixture installed in the bathroom of a Minnesota home built in 1961.

To stop the flickering light in this luminaire fixture I needed to replace the ballast.

Details of repairing dead, humming, dim, or flickering fluorescent lights are

at FLUORESCENT LIGHT REPAIRS.

Watch out: for flickering light safety hazards and take the immediate safety measures listed here.

18 Causes of Dimming or Flickering Lights or Electrical Power Loss at Buildings

Start by turning off any electrical appliance or circuit that is misbehaving. If you are not trained and familiar with safe electrical practices and repairs, keep your fingers off of the wiring - you could be shocked or killed or could cause a fire. Call for help from a licensed electrician.

Check your local telephone listings for licensed electricians or

see DIRECTORY OF ELECTRICIANS

1. Aluminum electrical wiring: if your building's branch circuit wiring (such as lights or electrical receptacles) was installed in the 1970's, solid-conductor aluminum wiring may have been used. With age, use, and mechanical disturbance, the connectors in an aluminum-wired circuit become unsafe, ultimately overheating.

   These connections can become hot enough to start a building fire without ever tripping a circuit breaker or blowing a fuse. We have had reports from homeowners of both conventional buildings and mobile homes or doublewides who described flickering lights that indicated trouble traced to aluminum electrical wiring.

   Watch out: for this fire hazard. If your home's branch circuits (receptacles and lighting) are wired with aluminum wire, flickering, dimming lights or even sparking may show up on just one circuit but the hazard is building-wide and significant. Turn off the misbehaving circuit and have the electrical system inspected and repaired by an electrician familiar with the hazards of and proper repairs for aluminum wiring.

   See ALUMINUM WIRING HAZARDS & REPAIRS - home - aluminum wire connections failing may cause flickering lights or loss of power

   Also see MOBILE HOME ELECTRICAL DEFECTS

2. Appliance or motor drawing high current: Any appliance that draws high current (amperage). Sometimes this is normal such as a brief high current draw when some large electric motors start, such as an air conditioning or heat pump compressor.

   An air conditioner or heat pump compressor motor may draw considerably higher amps at start-up than it does once the motor has begun to run.

   That's why installers should use a slow-blow fuse or slow-trip circuit breaker and it's why air conditioning circuit over-current protection ("breaker size" or "fuse size") is typically permitted to be one size larger (more amps) than the rating of the wire supplying the circuit.

   For example, an air conditioner may run on a #10 copper wire 30 Amp circuit but may be fused with a 35A or 40A circuit breaker to avoid nuisance tripping when the A/C unit is starting normally.

   But dimming lights can also mean that a motor is drawing high current because it is having difficulty starting.

   That in turn can be due to a motor that is seizing or due to a failing start-capacitor. Some of these conditions are unsafe. If the motor or appliance trips a circuit breaker, leave that appliance turned off until it can be repaired or replaced.

   See HARD STARTING COMPRESSOR MOTORS

   Also TIGHT or SEIZED AC COMPRESSORS

   See HARD STARTING ELECTRIC MOTOR CAUSES

   Also see ELECTRIC MOTOR DIAGNOSTIC GUIDE which describes steps & tests for both offline and online electric motor circuit analysis (MCA) test procedures for hard starting or non-starting A/C electric motors

   Technical note: see DATA TAGS on AIR CONDITIONERS for definitions of LRA (lock rotor amps) and RLA (running load amps).

   There you'll see that the data tag on an air conditioner or heat pump specifies two different amps or current ratings:

   the maximum circuit ampacity (for example 15A) that must be supported by the actual wiring - this is the current drawn when the motor is running

   and

   the maximum overcurrent protection (for example 20A) that is permitted on the circuit. Typically the data tag will also specify that the installer should use a time delay fuse or HVACR type circuit breaker.

   Watch out: many air conditioning and heat pump units are wired with multi-strand aluminum electrical wire - a perfectly legal choice.

   But because there is a higher risk of corrosion, resistance, and overheating at the connections of aluminum wiring, if your A/C or heat pump unit is causing severe light dimming or light flickering it makes sense to ask your electrician to check the condition of the wiring and its connections - that will reduce the risk of a total failure or worse, a fire.

   Watch out: When you can trace flickering or dimming lights to a single appliance, unplug it and stop using it until it can be inspected and repaired.

   If the appliance is a unit such as central air or a heat pump, switch it off at the electrical panel.

3. Corrosion from unanticipated sources: homes where Chinese drywall was installed were reported to have strange electrical problems including flickering lights.

   Off gassing from Chinese drywall was found to cause corrosion of copper components throughout some of these buildings, including HVAC components, cooling coils, and copper electrical wiring or connectors.

   See BACKWIRED RECEPTACLE FAILURE REPORT for an example of corroded electrical connections probably contributing to loss of electrical power

   See CHINESE DRYWALL HAZARDS

4. Electrical circuit breaker defects: some brands or models of circuit breaker are known to have significantly higher failure rates than that equipment in general. Examples include Federal Pacific Electric Stab-Lok circuit breakers and Zinsco circuit breakers.

   Watch out: fire or shock hazard: When you trace flickering or dimming lights to a specific electrical circuit, turn that circuit off at the electrical panel until your electrician can inspect and repair the problem.

   See CIRCUIT BREAKER FAILURE RATES - a bad circuit breaker or electrical panel connection can cause flickering lights or loss of power. This article lists common or well-known problem circuit breaker or electrical panel brands or models.

   Since a failing circuit breaker or device sometimes (not always) suffers internal arcing that produces a buzzing sound, that clue may also be diagnostic. Switch such circuits off.

   See NOISES, ELECTRICAL SYSTEM

5. Electrical circuit wiring defects: specific electrical circuits may be dimming or intermittently losing power if the wiring has become damaged or its electrical connectors are loose. Typically this problem shows up first on just one electrical circuit, or on all of the lights or receptacles ("wall plugs or outlets") downstream from a specific point (where a problem has occurred). A double-wide homeowner reported loss of lights on just one side of a room.

   After confirming that no GFCI device had tripped causing a power loss and no circuit breaker had tripped, the owner needed to ask for help from an electrician to find the open wire. For examples

   See BACK-WIRED ELECTRICAL DEVICES - home - poor connections lead to flickering lights and loss of electrical power

   See BACKWIRED RECEPTACLE FAILURE REPORT - corrosion and poor electrical connections in a beachfront home lead to loss of electrical power

   See KNOB & TUBE WIRING

6. Electric fan or LED bulb induced "light flicker": when certain fluorescent or LED lights or in particular when an overhead fan is in use, depending on factors such as the location of light sources and fan in the room, fan speed, fan blade size and who knows what else can cause an apparent flickering of light where the fan is located.

   This is not an electrical problem but one of light and shadow. However depending on the flickering light speed, this condition can be uncomfortable for some people and may be hazardous for some who have particular medical concerns such as light-sensitive epilepsy. Video games and TVs can also produce flickering light that can be a problem for the same occupants.

   • Dahlquist, Neil R., James F. Mellinger, and Donald W. Klass. "Hazard of video games in patients with light-sensitive epilepsy." JAMA 249, no. 6 (1983): 776-777.
   • Romero‐Gómez, Manuel, Juan Córdoba, Rodrigo Jover, Juan A. del Olmo, Marta Ramírez, Ramón Rey, Enrique de Madaria et al. "Value of the critical flicker frequency in patients with minimal hepatic encephalopathy." Hepatology 45, no. 4 (2007): 879-885.
   • Wilkins, Arnold, Jennifer Veitch, and Brad Lehman. "LED lighting flicker and potential health concerns: IEEE standard PAR1789 update." In Energy Conversion Congress and Exposition (ECCE), 2010 IEEE, pp. 171-178. IEEE, 2010.
7. Electric motor defects: motors drawing high or excessive current can cause dimming or flickering lights

   CAPACITORS for HARD STARTING MOTORS - a hard-starting motor drawing high current may cause flickering lights

8. Electrical panel defects: as we cite for circuit breakers, some electrical panel brands experience failures far more often than is generally the case among their peers, often because of innate design or manufacturing problems. Some of these electrical panel defects show up as flickering lights, dimming lights, or loss of power on one or more electrical circuits.

   See FEDERAL PACIFIC FPE HAZARDS

   Also see ZINSCO SYLVANIA ELECTRICAL PANELS for examples.

   A complete list is at ELECTRICAL DISTRIBUTION PANELS in buildings, safety for electrical inspectors, electrical panel, fusing, wiring defects, defective products.

   Also see CORROSION in ELECTRICAL PANELS - corrosion on electrical wire or components can cause flickering lights or loss of power

9. Electrical service supply defects & voltage fluctuations: depending on where you live, weather, loads on the community electrical system, age and condition of the electrical grid and power generation can cause dimming or flickering lights. If this is the source of trouble at your building, your neighbors will see the same conditions as you.

   Sometimes we monitor voltage being delivered to a building to check the range of voltage variation but of course if your electric company's supply is varying significantly, you and your neighbors will all see dimming lights or total loss of power. Problems at a local power transformer can cause the lights of your home and those of your neighbors to flicker or dim or go out entirely.

   Some light flickering, outages that last 60 seconds or less, are referred to in the power industry as "momentary outages" while voltage drops - not a total loss of power but a reduction in the voltage being delivered to a building are referred to as "voltage drops".

   According to Florida Power and Light (FPL), these may be caused by lightning strikes, damaged electrical equipment, animals interfering with electrical equipment (including a mouse in your electrical panel), and in coastal areas, salt spray that affects power company equipment or wiring.

   A "voltage sag" - momentary drop in the voltage level below its nominal 120VAC - may also occur, which explains why some lights may dim. These conditions can re-set or stop operation of computers and other electrical devices unless you have a battery-backup uninterruptible power supply (UPS) installed. - FPL "Power Flickers - Reducing Power Flickers", Florida Power and Light, retrieved 9 Nov 2015, original source: https://www.fpl.com/reliability/power-disturbances/flickers.html

   According to Canada's CCOHC, "Usually voltage fluctuations are small and do not have adverse effects on electrical equipment. However, in offices, for example, voltage fluctuations of just a few tenths of one percent can produce very annoying flickers in the lighting, especially if they are regular and repetitive in the 5-15 Hz range." - CCOHS (2015 cited below)

   See ELECTRICAL SERVICE ENTRY DAMAGE - damaged electrical feeders or service entry can cause flickering lights or loss of electrical power

   See VOLTS MEASUREMENT METHODS

   Also see DOUBLE FAULT, LOSS OF ELECTRICITY where we describe faulty wiring at a single building that led to flickering lights and ultimately, loss of power.

10. Electrical service connection failure: a loose connection at the building's electrical service entry cable or damage to the service entry wiring itself can cause flickering lights or loss of power. I've seen this problem occur in one side of a 240V electrical panel, causing ultimate loss of power to half of the electrical circuits in the home.

    See SERVICE ENTRY WIRING & AMPACITY

    Also see ELECTRICAL SERVICE ENTRY WIRING - how is electrical power brought to the building: inspection, troubleshooting, defects

11. Electrical neutral connection failure: if the electrical system's neutral connection or neutral wiring is faulty, such as a loose connection in the electrical panel, lights in the building may sporadically flicker or dim or power may even be lost intermittently.

    I've seen this problem occur when a metal fence post was driven through an underground feeder. A case history that was finally resolved by finding a problem with the electrical utility company's neutral is given

    at FLICKERING LIGHTS, LOST NEUTRAL

    See also LOST NEUTRAL SHOCKS HOMEOWNER

12. Fluorescent light ballast & other light bulb problems: fluorescent lights that use a ballast to produce the voltage needed to drive the light fixture may suffer from a ballast failure. The ballast, a "black box" found inside of fluorescent light fixtures may cause humming or buzzing sounds heard near the light fixture as well as flickering lights.

    This problem occurs where older magnetic type ballasts are installed. Newer electronic ballasts don't hum or buzz.

    See FLUORESCENT LIGHT REPAIRS where we describe repairing flicking fluorescent light fixtures.

    Also see LIGHTING, INTERIOR GUIDE where buzzing ballasts are discussed.

    Separately we discuss eliminating the ballast entirely by switching to an LED bulb - an option available for some fluorescent fixtures.

    See LED BULB REPLACES FLUORESCENT

13. Lightning strikes can damage both area electrical wiring or the supply grid as well as damaging components at an individual building. A frequent sufferer of lighting strikes are well pumps and well pump wiring at properties where a submersible well pump is in a steel-casing well in an area subject to frequent lightning storms.

    In this case the problem is usually confined to the well circuit, but I have participated in investigation of more extreme damage to all of a building's wiring and even plumbing systems due to lightning strikes.

    See LIGHTNING PROTECTION SYSTEMS

14. Light fixture or light bulb or bulb socket / wiring defects: flickering lights that occur only at a single light fixture may be caused by a failing or defective light bulb, particularly if the bulb is a traditional incandescent type.

    As the filament in an incandescent light bulb begins to fail it may become loose and intermittently "open" electrically causing the light to flicker. Tapping gently on such a bulb may cause it to go out completely. Changing the bulb should fix the trouble.

    If the individual light fixture continues to flicker after a new bulb has been installed, check that the bulb itself is ok by trying it in a different light fixture.

    If the light bulb is not defective then I suspect a bad bulb socket in the light fixture or a loose wire connection in the light fixture's connection to its power circuit. Turn the fixture off until it can be repaired or replaced.

    A loose, corroded, or cracked, broken bulb connector or incandescent or LED bulb socket can also cause flickering lights. [Thanks to reader Jan for reminding us of this cause, 2020/10/29 ]

15. Loose electrical connections in an electrical circuit: loose splices or connections anywhere in an electrical circuit can cause flickering lights. Usually this defect shows up just on the circuit that contains the faulty connection. I've seen this problem at an electrical receptacle that received very frequent use: devices were constantly plugged-in then removed.

    The wiggling and jiggling of the device loosened contacts intended to be made between the receptacle and the wall plug. Other receptacles or switches may be wiggled around in their electrical box (if poorly-secured) causing loose, failing electrical connections.

    See ELECTRICAL SPLICES, HOW TO MAKE - a bad splice, wire connector or loose screw or wire can cause flickering lights or loss of power

    In some cases, such as back-wired push-in type electrical receptacles, the wiring connector itself (a small spring) is inherently weaker than screw-type connectors. On older homes these connections can fail, occasionally leading to a fire.

    See BACK-WIRED ELECTRICAL DEVICES

16. Low or varying voltage from the electrical service utility or due to defects in the service drop or service entry wiring.

    VOLTS MEASUREMENT METHODS - voltage variation may cause flickering lights

17. Outdoor electrical wiring defects: aside from the service entry cable problems I've cited, other outdoor wiring defects can cause flickering lights on those circuits. Examples include lighting fixtures or receptacles that have become wet.
18. Something else is wrong: the list above is certainly not exhaustive and there may be other causes of flickering or dimming lights that we should add here. Please use the page bottom CONTACT link to let us know what we've missed or add a comment in the Comments section below.

Watch out: flickering or dimming lights may, depending on the cause, indicate a dangerous condition. Arcing or overheating at electrical circuits can ultimately lead not only to power loss but to a building fire. That's why we recommend turning off misbehaving electrical equipment while you wait for the electrician.

What Level of Flickering Light Can People See?

Canada's CCOHS has written some of the most easily understood description of who sees flickering lights, what people can see or sense, and what health effects may occur when exposed to flickering light. Excerpts are below:

People can see lights flashing on and off up to about 50 flashes per second (50 Hz) - they are most sensitive to time-varying illumination in the 10-25 Hz range. The actual critical flicker frequency increases as the light intensity increases up to a maximum value, after which it starts to decrease.

When a light is flickering at a frequency greater than 50 or so Hertz, most people can no longer distinguish between the individual flickers. At this frequency - the critical flicker frequency or flicker fusion threshold - the flashes appear to fuse into a steady, continuous source of light. This happens because the response to the light stimulus lasts longer than the flash itself.

Most people cannot notice the flicker in fluorescent lights that have a flicker rate of 120 cycles per second (or 120 Hz).

The light flicker may be detected by its stroboscopic effect. When objects move or rotate rapidly, they may be lit at or about the same position during each cycle or rotation.

This makes objects look as if they are moving more slowly than their actual speeds - they may even appear stationary if the object is moving at the same rate as the flicker frequency (or a multiple of it).

This fact is the principle behind a strobe light but it is not the desired effect in general lighting. In fact, it could be a safety hazard if someone mistakenly thought that some equipment was stationary or was moving slowly. - CCOHS, "Lighting Ergonomics - Light Flicker", Canadian Centre for Occupational Health and Safety, CCOHS, retrieved 2015/11/09, original source: http://www.ccohs.ca/oshanswers/ergonomics/lighting_flicker.html

Also, from a different source, we see that flickering light can be a source of eye strain and headaches even if it is not related to electrical malfunctions that we listed earlier in this article:

... the use of high frequency electronic ballasts (20,000 Hz or higher) in fluorescent lights resulted in more than a 50% drop in complaints of eye strain and headaches.

There tended to be fewer complaints of headaches among workers on higher floors compared to those closer to ground level; that is, workers exposed to more natural light experienced fewer health effects. - Wilkins, A. J., I. Nimmo-Smith, A. I. Slater, and L. Bedocs. "Fluorescent lighting, headaches and eyestrain." Lighting Research and Technology 21, no. 1 (1989): 11-18.

Flickering lights traced to bad utility company neutral wire

This topic has moved to FLICKERING LIGHTS, LOST NEUTRAL

Reader Q&A - also see the FAQs series linked-to below

@Robert,

Your electrician may find some things to check besides the rather lengthy list of causes of flickering lights that we give above on this page, but I hope you will review that list, as it's more complete than I can make up de novo here.

Remember to check carefully the connections on any aluminum wire circuit connections such as may be powering an electric water heater.

My lights flicker when my 80amp tankless water heater is running. It is hooked up to my main 200amp service box and the lights are on connected to my inside 100amp box inside.

@Mahmoud Salem,

It could be a bad circuit breaker but more likely is a loose electrical connection, or one of the other causes listed in the article above. Please look through that information and keep me posted.

Hi, The lighting in the top floor flickers and the circuit breaker turns to off. No signs of burns or cut wires. Is the circuit breaker faulty? Took it to shop and was checked and I was told it was ok! Thanks

@Robert Gillitzer,

For sure a loose or overheating connection anywhere on the circuit, from the electrical panel to the light fixtures and receptacles involved could cause flickering lights.

By the way, usually we don't put both receptacles and fixed lighting on the same circuit.

I have one circuit that has several outlets & 3 lights on it. When I switch on any of the lights, or plug into one of the outlets, that one or all, depending if I have more than one light one, all will flicker.The light switches have been replaced, but the lights still flicker.

Is it possible for one of the switches or outlets to affect any or all the connections on that line? Or should I be looking at the main box for a loose connection of that line. All the other lines in the house are ok.

@Warren,

Most likely the cause of your flickering lights is one of those described above on this page.

Watch out: there are some brands of electrical panel (e.g. FPE Stab-Lok, Zinsco, and others) and some electrical wiring (solid aluminum branch conductors) for which flickering lights are a big red flag of imminent danger of a building fire.

i have a separate part of the house that has a sub panel with 4 breakers and from time to time different lights within those 4 circuits goes out randomly and then randomly come back on without tripping any breakers what could be causing this type of problem ?

On 2021-10-29 by inspectapedia.com.moderator - problem circuits need diagnosis

@James D,

That sounds like a wiring error or possibly, if we're lucky, simply a loose electrical connection somewhere on that circuit.

But

Watch out: such connections can be dangerous, causing arcing and overheating.

• How old is the home?
• When was the wiring job done?
• Was the installer a trained, licensed electrician?
• Were aluminum wire or aluminum components used ? (A particular fire hazard for branch circuits)
  

Best would be to get an experienced, licensed electrician to trace and diagnose the problem circuit.

Depending on what she finds, that in turn may be suggestive of inexpert workmanship; if so then further inspection of the home's wiring and electrical panel and devices would certainly be justified.

I have a small LED night-light that is plugged into a wall socket in my bedroom. My question is when I use the TV remote (Fire TV) it makes the night light flicker. Also, when we turn off or on the ceiling fan/light switch, a small table side lamp (that can turn on and off when you touch the base) will turn on if the table lamp is off, and off if the table lamp is on. I am worried about how our home was wired since the contractor was "El Cheap-o" on materials and labor. Any thoughts or suggestions?

@dave,

Of course there could be another problem but the common explanation for the flickering lights that you described would be a loose electrical connection at the switch or a feeling switch. I would have the switch replaced.

we turn om lights to the house and lights flicker after a period of time when dimmer switch is on why?

On 2021-07-24 by mak.church (mod) - too much current draw for a 15A but not 20A circuit

@Sully,
In the above article, there are a number of diagnostic steps that are worth looking at. Because of your reference to both 15A and 20A circuits however, pay specific attention to the section:

18 Causes of Dimming or Flickering Lights or Electrical Power Loss at Buildings

and the #2 item there: Appliance or motor drawing high current

Perhaps the high current draw in this case is just enough to blink or dim lights on a 15A but not on a 20A circuit.

A guess is that the two devices you cite are drawing a moment of high current at start-up (not un-common). On a 20A circuit the current drawn is tolerated because the circuit permits a bit more current than the 15A wires;

A corroded or loose connection in a circuit or in a panel might cause that trouble too, but as you're seeing it on both sides of the panel I suspect our first guess is the right one.

Let us know if you have additional questions.

The lights on all 15a circuits in entire home blink momentarily when HVAC compressor or vacuum cleaner plugged into 15a outlet starts? 20a circuits don't seem to be issue. Blink happens for both L1 & L2 circuits.

@John,

Thanks for the added detail; keep us posted;

Certainly some of my warnings will err on the side of safety.

See USING an ELECTRICAL RECEPTACLE TESTER to CHECK VOLTAGE & WIRING

Watch out: an electrical receptacle with reversed polarity can be unsafe and in some cases can damage electrical equipment. It may not be obvious, after all it's "alternating current" running in "two directions" on the circuit, between hot and neutral.

But keeping the neutral side "live" as what happens in reversed-polarity circuits can actually damage some printed circuits and control boards by delivering power where it is not expected to be fed.

@inspectapedia.com.moderator, thank you. I will definitely not be attempting to investigate or fix beyond what you suggested. I have a great deal of respect for this things and experienced electrical shock as a child!

I just recalled that when we bought the home we did have an electrician over as part of renovating two rooms. He replaced some switches and install a number of new outlets. He did find two switches quite old that needed replacing. My hope is that he would have noticed the aluminum but I'll have someone check regardless.

However I believe he did not investigate or check the other rooms in the home as I just checked a number of outlets in these rooms and they have reverse polarization which I know is not usually a big deal but thought to ask if it could have any relation to the issue with my computer.

The outlet the computer and monitor are plugged into has reverse polarization.

@John,

Your electrician will be able to tell immediately if there is aluminum wiring in the electrical panel when she opens the panel cover to inspect the circuits inside.

That's not something you should do as you could be shocked or killed.

However if you look at any electrical wiring that is visually accessible you may occasionally see printed on the plastic covering of plastic wire the word "aluminum" which would be significant.

You can also use the on-page search box to search this website for

ALUMINUM WIRING HAZARDS & REPAIRS - overheating or corroded connections can cause flickering lights

For an article describing other wiring text or imprint or size that identifies it as an aluminum product.

From the age of your house, the original wiring would not be aluminum.

@mak.church, Thank you. I think the work done in the 1970s was to increase the amps in the home. I confirmed it was not done by a electrician - instead it was done by a family member who is very handy with homes. (Make me nervous). The home was built in the late 1940s and is a two family. It now has 100 amps per apartment.

Is there anything I can do that would help you identify whether I have aluminum wiring such as taking a photo? I will have an electrician come to check regardless but appreciate an unbiased opinion

@John,

Except where your electrical wiring was improperly sized in the first place or where it has been damaged by a building event such as a fire, it is quite rare that it is ever necessary or even appropriate to replace the wiring itself. Copper doesn't wear out. Copper thousands of years old has been found intact in the Egyptian tombs.

It could be a problem with connectors, or an overloaded circuit. Simply turning on the bathroom light should be such a trivial load on the circuit but I suspect there is an unsafe connection or switch for which you need an electrician who will locate and fix the connector, switch, or device.

Because it's expensive to bring an electrician to a property for a single small problem, that would be a great time to have the electrician add a dedicated electrical circuit to the room where you use your computer.

Watch out: 1970s electrical wiring could include aluminum solid conductor branch circuit wires. If your home has aluminum wiring and the wiring has not been properly repaired by installing the special connector at each and every connection then that circuit is unsafe and is a fire hazard.

So be sure to have your electrician check promptly for the presence of aluminum wiring. Let us know what you're told.

Hello, i bought a house that had its electrical wiring updated in the 70s. When they did it, they did not dedicate a circuit for each room so some rooms share circuits.

In my small office I had my computer with monitor and when someone turns on the bathroom ceiling light my computer monitor power turns off - it does this consistently.

I am worried because the computer monitor is LED, uses low power and the light bulb in the bathroom also is LED.

I do not have any high intensity applicances on in my room, just laptop, LED monitor and sometimes a fan and light.

Does this indicate bad or wiring that should be replaced? My concern is that the previous owners were very frugal and likely has the wiring done by unlicensed electricians.

@Cori,

Before the electrician leaves ask him to observe whether there are any flickering lights and ask him if there's something else that he recommends

I have flickering and dimming lights thought out the whole house. Electrician is here now.

He is replacing my outside main wire and will replace 3 or 4 breakers on panel but says it' NOT GUARANTEED the flickering and dimming lights will stop. R u kidding me?? I'm paying him $1850.00!!!

@Zach,

That sounds like a shorted electrical circuit, switch, or fixture.

Your electrician will probably use a DMM or VOM to check for shorting and check the current draw on each of those circuits and also she'd inspect the electrical panel itself, the breakers and the bus - for arcing.

Is there aluminum circuit wire in the building?

What's the electrical circuit brand?

How old is the building?

Whenever I turn my kitchen light on my dining room fan/light combo dims. It stays dim until I turn kitchen light off. At first I thought it was possibly in the switch as it's a double switch with power hooked to the top that controls both the top and bottom switch. There is also a 3way switch in the same location ran on a separate breaker.

I turned off both breakers took both the dining room light and kitchen light off the switch and hooked each one directly to the power feed with wire nuts. One connected to one circuit and the other connected to the circuit that the 3way had been on. I flipped on one breaker and dining light came on. I flipped on the other breaker and kitchen light came on.

Again dining room light dimmed as before. I've checked and tightened all wiring going to both fixtures. Help!

If that were my home I'd have a licensed electrician trace the circuits involved, both to find the arcing or loose connectors, other unsafe connections and devices, and/or to get clear on what's wired on what circuit: we may need to add circuits to correct an overloading problem as well as fixing the wiring problems.

Recently I had a circuit that controlled 3 outside motion lights fail. I checked for proper voltage at the switch and got "0" voltage reading. Then I checked for voltage at the circuit breaker and it measure 117v.

Then two days later I'm assuming the same or neighboring circuit failed which controls 5 outlets which have a washer, small firdge, garage door opener, and some small devices.(6outlets) I noticed that all of these circuits arent even isolated to certain areas of the house , they seemed to be mixed up.

this house was built in the 60's with what appears to me as some renovation along the way with poorly added circutry. 3 years prior to all these issues dimming of lights when washer and or dryer is in use, as well as bzzing in swiches was present.

Any comments as to what the next step or solution to this problem would be is greatly apreaciated.

This diagnostic discussion has moved to its own page

at FALSE GROUND, BOOTLEG & FLICKERING LIGHTS

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Continue reading at FLICKERING LIGHTS, LOST NEUTRAL, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

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