Why is my power flickering across multiple circuits?

Question

I woke up this morning and went downstairs to find that none of the lights would come on (lights were working fine upstairs). My first instinct was thinking that a breaker had tripped, so I went to the breaker box and checked everything. Nothing out of order. I started investigating a little bit more and discovered that the power was not actually out... just flickering. If I turned on lights, they would occasionally flick and try to come on and then go back out. The dishwasher kept clicking like a relay was opening and shutting continuously. I went downstairs to discover that the fan for the heat kept trying to spin up and then dying.

My second hypothesis was a simple loose wire at a switch or outlet... but that can't be the problem either. The problem is affecting about 50% of the circuits in the house, seemingly at random. Fridge works, range is out. Basement lights are fine, basement sockets are dead. Etc. A loose wire would only affect one circuit.

I killed power to everything but the fridge to prevent damage and went to work. I plan to take a look again when I get home. Any ideas what may be going on?

Things that might be related or might be a complete coincidence:

• We recently (work finished a week ago) had a deck put on. This required an electrician to move an indoor outlet, add an outdoor outlet and light, and install a switch for the outdoor light.
• It also just got cold enough for us to turn the heat on. Last night was the second night it was on this year. When I got up, it was 63 degrees in the house because the heat could not actually turn on.

Answer 1

Sounds like a classic compromised leg of your main service. This problem could be anywhere from the connections at the utility transformer on the pole, to the connection taps on the side of the house, to the meter pan, to the main breaker.

IMO this is NOT something for a DIY to troubleshoot since you would need to be testing live unfused wires in places that are inaccessible to a homeowner, such as inside the meter pan.

I would start with calling your utility and explaining to them the issue. If they find no problem call an electrician to check the equipment in your house.

Answer 2

This is definitely an issue with one of the legs of your main service. This pops up most commonly when the temperatures outside start to change and cause the wires to contract or expand. The power coming in to your house is normally fed by two separate wires, if one of these has become loose, you will see issues on about half the circuits in the house.

Answer 3

I know this thread is super old but I hope it can help someone else seeking answers. I had the exact same problem, random parts of the house had electricity while other didn't. At some points the lights were flickering, then they stopped. Refrigerator and microwave worked but stove didn't. Checked the box but that wasn't the issue. Shortly after I received a text from my electric company advising of outage. The trucks came out and after 4 hours, problem was fixed. I was thinking the problem was inside, never had random parts of the home with a power outage. If this happens to you call the utility company!

Answer 4

Since it became cold enough for you to turn on your heat last night, other people probably did the same thing. This means a surge in load on your utility company's entire grid...and the grids it connects to.

This can result in brownouts, greyouts, and blackouts within the utility company's service area. In the US, this is less common than other parts of the world, but still happens from time to time.

I'm not saying this is the cause, but it could also produce the symptoms described. The deck addition is likely to have produced immediate problems and those problems are likely to be more localized.