What causes the lights in my house to dim?

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What causes the lights in my house to periodically dim and brighten?

There are several causes of dimming lights:

If your lights dim momentarily when an appliance such as an air conditioner, washing machine, furnace, or refrigerator comes on, it may be that the lights are wired on the same circuit as that appliance. You can easily verify it by turning off the circuit breaker associated with that appliance and see if the dimming light also turns off. This is not necessarily a dangerous scenario, but if you’re worried about it, it would be worth a call to a licensed electrician to investigate. These types of appliances tend to draw a lot of power when they first turn on, which is why they are usually connected to a dedicated circuit in the service panel. Owners of older houses may find that these appliances are probably sharing circuits with other loads. If necessary, your electrician can install dedicated circuits for these devices to help alleviate the dimming problem.

If this is a new symptom, another possibility is that you could have a loose wire connection, possibly in the breaker panel or a problem with the neutral line. We usually see this type of problem manifest itself during summer months when demand for electricity is higher, and it will stress an already-loose connection that didn't show signs of trouble in colder months when demand was lower.

If all the lights in your house dim periodically or all the time, or even get brighter and possibly burn out occasionally, the problem could either be with a loose or bad connection in your circuit breaker panel or electric meter, or with the utility line feeding your house. Many times, this type of problem is due to an overloaded utility transformer on the street. This happens over time as more houses are built in your neighborhood, thereby increasing the demand on the existing utility wiring. A quick call to your utility company repair department can dispatch a technician to see if the problem is on their lines. If the problem is not with the utility lines, then you’ll need a licensed electrician to check your service entrance equipment for problems. You should not ignore this symptom, as it may be a sign of a possibly dangerous problem.

One other cause of dimming lights in your house could be due to an undersized service. This is usually more of a problem with an older home than one built in the last 20 or 30 years. Houses older than this (and especially house with fuse boxes instead of circuit breakers) do not supply enough electrical current to power the appliances and other technology that we all have in our homes today. Again, if this is the problem you’re experiencing, then an electrician can perform a service upgrade, which will bring enough power into your house to handle all of your needs for the foreseeable future.

We just got new carpet installed in our house and we noticed that when they were pounding it into the tacks upstairs, the lights would flicker. That same day, 5 of 7 lights in the downstairs ceiling (just below the bedroom that got new carpet) stopped working. Is it possible that something short circuited as a result of the pounding on the upstairs floor?

Probably not. Most likely the bulbs in the fixtures are loose and need to be re-tightened.

The light in my living room quickly dims then goes out every time we turn it on. What do you think the problem is?

You may have a loose neutral connection somewhere in the circuit between the circuit breaker and the fixture. The capacitance of the wire allows the light to turn on briefly when the switch is turned on. Check all the junction points (both line and neutral) for tight connections.

Wurtsboro Electric Service, Inc.

Licensed electricians serving Orange county, Sullivan county, and Ulster county in New York
(845) 888-8000 

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