How to Fix a Hum in a Phone Line
Ask Danny, Electrical and Lighting, Repairs and Installation by Danny Lipford
I have a loud hum in our telephone line. The phone company says it’s inside the house. Is there any type of a device that can locate the cause of the problem? – Jim
Hi Jim,
There are a number of things that can cause humming or static in a phone line including a short in the wires, a defective phone, interference from power wires or light fixtures, and a signal from another electrical device. Here how to go about isolating and repairing the problem:
- First, check to be sure the hum is coming from inside your home by opening the telephone interface box, disconnecting the test jack, and plugging a corded phone into it. If you still hear the hum, then the problem is with the phone company. If it stops, the problem is inside your house.
- If it’s inside, plug the house jack back into the interface box and unplug each phone in the house one by one while listening in on another extension. If the hum disappears, the problem is with the phone you unplugged.
- If the hum persists, disconnect each set of wires one by one from the terminals in the interface box, and listen on an extension until the sound stops.
- Once you’ve isolated the problem wires, check the connections at the jack, and try unplugging any electrical devices nearby that could cause interference.
- If you’re still having problems, hook the other two color coded wires in the cable to the jack and interface box.
- As a last resort, permanently unhook the defective wires at the interface box and run a new line from the interface box to the jack.
You can find out more about working on phone lines in the articles:
6 Comments on “How to Fix a Hum in a Phone Line”
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December 28th, 2008 at 6:57 pm
I have the line with all these colored wires coming out which color goes were i know red to red and so on but what about the blue brown white on one side green on other where does the green go or the blue if the colores on the box are red black yellow and green but there’s orange on the wire
April 29th, 2009 at 11:40 am
If the hum is coming from the power lines above the phone
lines, have the power company disconnect the power lines.
May 14th, 2009 at 2:48 am
I want to install a Digital Cordless Phone and the instructions say I need a RJ11C type modular telephone
jack. Why can’t I just use the standard jack already
installed in my home. Also can I get info on installing
a RJ11C type from your website?
September 13th, 2009 at 9:40 pm
We had a persistent hum in our phone. To the point where we were buying new phones to try and get rid of it. The phone company sent a guy and he said it was our problem, not the phone company. We put up with it for a while. Then, we had some DSL problem and the phone company sent a different guy out. He heard the hum. It wasn’t OUR problem after all. He followed the hum all the way to the phone company equipment one mile away from us. He fixed whatever it was and I thanked him profusely. My bad that I didn’t get his name and write to the company.
Ben Erickson Says:September 14th, 2009 at 8:02 am
Hi Marym,
Thanks for relaying your experience. I had a similar one a while back. Everytime it rained there was loud static on our phone line, but by the time the phone company would get by to check it out, the weather had cleared and the phone was fine. Finally, the arrrived in bad weather and traced it back to a bad connection on the pole a block away.
September 17th, 2009 at 5:13 pm
Great website!! I love the visuals it is a huge help when doing the project.
Thank you