Diagnose cause of voltage fluctuation in house

Background

• My house has 100 amp service with all copper wiring and all wiring contains a hot, neutral and ground wire.

• The past three weeks the lights in the house go dim and bright. The fridge makes a little noise when the voltage drops/spikes. It happens sporadically and some days it won’t happen at all, other days it happens frequently throughout the day (no pattern to the time between occurrences).

• The load doesn’t seem to affect when this happens.

• When the problem first appeared I started checking the voltage on the panel. When it happens one leg will drop down to around 118 volts for a few seconds, when it typically stays around 122 volts. One time one leg spiked to 169 volts.

• As i’m writing this message the fluctuation in voltage has happened at least five times, no load change in the house has occurred over that timeframe.

What I have done

• I had an electrician come check the panel and verify I have no loose neutrals. He said the power company is to blame. He checked out the panel and didn’t find any issues. Unfortunately the spike / lowering of voltage didn’t happen while he was here. I called power company.

Here is how my visits w/ power company has gone:

• Visit #1: Technician comes out, checks voltage at meter. Monitors voltage for a few minutes, no problems arise then leaves. Declares no problems on their end.

I start watching the neighbors house to see if they are getting any power fluctuations. I notice it is happening for them also. I speak with the neighbor and they claim it has been happening for months to them. They thought it was wiring in their house. Unfortunately they are renters and they can’t be counted on for any help.

• Visit #2: Technician comes out, I’m home this time. He monitors voltage and has me put load on the system. Everything checks out, nothing happening. I tell him neighbors experiencing same issue. He says not seeing anything, will do a ‘line trace’ in a few days.

• Visit #3: Three technicians come out they check voltage at my meter, let it run for awhile. they check neighbors meter, find neighbor has issue in the meter and they fix the issue. They still don’t see anything happening at my meter.

They say the transformer is relatively new and say it can’t be the problem. As they are walking around the poles and other houses, I look at the volt meter they have installed at my meter and it drops down to 118 volts. I mention this to technician and he says that shouldn’t happen.

I ask one of the technicians if something was going out in my neighbor’s house could that impact my voltage? I said they have been running their AC all the time. He said it should have a thermal overload and not cause any issues w/ other neighbor’s electricity, but he has seen where things fail and it can cause issues.

Technician’s leave saying these things can take time and need to be patient.

What to do next?

I’m far from an expert on this, so any help is appreciated. I don’t want voltage fluctuations harming things in the house.

Could something in my house be going bad which is causing the issue? Should I start turning off circuits in the house and see if the problem occurs? Would that be one way to troubleshoot the issue?

I’m afraid the burden of proof is on me now regarding the power company.