Help me fix my home phone wiring.
July 17, 2005 11:22 AM   Subscribe

Why does my home phone system sometimes ring only once when someone is trying to call me?

This happens about 30% of the time. The caller hears the first ring, then silence. Eventually, the connection disconnects. However, as I discovered today, if I pick up the phone after it has stopped ringing, the call connects. So it's just the actual ringing that's failing, not the connection itself.

I checked the line at the outside box, and it's fine. So the problem is on the inside of my house.

And that's where it gets interesting, because 13 years ago, when we moved in, there were just two phones in the house. I wired everything else (6 phones, two lines) myself. We've never had any problems with it until recently, so something must have gone wrong.

What am I looking for? Is there a tool that would help me find the problem, which I'm guessing is a problem wire? Does it matter that some of the lines run up the back of the house along the airconditioner drain and into the attic (I used standard four color phone cable, wrapped in the round cord)? Should I just give up and go completely wireless?

Thanks for any advice.
posted by baltimore to Technology (10 answers total)
Does it happen 30% of the time, regardless of time or day or other factors? i.e. If you receive 10 calls in a row, can you be fairly certain that at least one of them will exhibit the problem?

If so, the first thing I'd do is to disconnect the house, plug in a phone to the outside box, and run the test. If everything's good, start connecting up parts of the house at a time and retesting.

You might also want to add up your RENs (ringer equivalence numbers), I hear they're not supposed to total more than 5 per circuit, otherwise there can be ringing problems. (Not enough current to drive all the ringers.)
posted by trevyn at 12:06 PM on July 17, 2005

The first thing I would suspect is a defective phone. That's more likely than defective wiring. I say that because unless there is physical damage to the wires (rodents, something falling on/against them, etc.) wires don't just "go bad" on their own. (That's why the inside wiring maintenance plans the phone companies sell are one of the biggest rip-offs and money-makers for the phone company.) Start checking out the phones. And be careful with the terminology. When you said "phone system" I thought you had a PBX in your house.

Also as already mentioned, make your you don't exceed 5 REN or so. Each phone should be labeled with a REN. A REN of about 5 is OK. If you are a long way from the central office, you may not get 5; closer and you may be able to go higher. If you have any older mechanical bell phones, these will have a much higher REN (typically 1.0 for a real bell, by definition) than electronic tweeter type "bells" (which may have a REN as low as 0, meaning they draw virtually no ringing current from the phone company).

The fact that this just started and you made no other changes to your phones suggests to me a defective phone though.
posted by AstroGuy at 12:44 PM on July 17, 2005

The caller hears the first ring, then silence.

I could see phones not ringing for various reasons, but the caller should hear a ring until the circuit is opened.

A couple ideas..
Do you have a fax machine or fax/voice switcher on the line? Some of these will pick up the line quickly but should at least play something back to the caller, even if it is a funny sounding ring.

An answering machine, perhaps, with an electronic message that has been erased, leaving silence? Some answering machines had a "toll saver" feature that picks up after only one ring, if there are new messages.. (So if you call to get them and it rings twice, hang up and save long distance).
posted by SpookyFish at 12:59 PM on July 17, 2005

I knew I'd forget to mention something...

While trying to isolate this, I pulled all phones and answering machines offline, except for one hardwired phone plugged into one of the two original outlets. So I did try to control for faulty equipment. Not knowing about RENs, I unwittingly controlled for that as well by doing this.

We don't have any mice, as far as I know.

I did take the phone outside to the junction box and plug it directly in there. I made 10 test calls - all worked fine. Also the second line into the house (an old fax line - I've got to cancel that thing) works fine.

The only other thing that occurs to me is the security system, which is tied into a phone line, though I think it's the second line. I'll try taking that offline later tonight (and, no doubt, hearing immediately from the security company!).

This one's a real mystery. Thanks for the help so far.
posted by baltimore at 1:35 PM on July 17, 2005

Trevyn: It happens any time. 30% is just my guess on the frequency. It can happen two calls in a row and then the next four will be fine, then bad, then good, etc.
posted by baltimore at 1:37 PM on July 17, 2005

This happened to me. I found corrosion in an unused modular jack. I disconnected the wires from the jack and that fixed the problem.
posted by Mack Twain at 3:37 PM on July 17, 2005

Aha, you didn't mention the security system. Properly wired in, they are designed to grab a line, even if in use, so it's possible that there is a problem with the controller. I'd definitely check that. When something that has been working for a long time suddenly stops, I would suspect electronic device failures (phones, security system controller) before wiring. Like I said, unless disturbed somehow, wiring just doensn't fail like that.
posted by AstroGuy at 3:43 PM on July 17, 2005

Not to mention, the trouble symptom just doesn't sound like a wiring issue to me.
posted by AstroGuy at 3:44 PM on July 17, 2005

Bingo! It was the security panel. Thanks AstroGuy and everyone.

Now I have an answer.

And a broken security system.

posted by baltimore at 4:35 AM on July 18, 2005

Might not be broken...

Many security systems will pick up the line if your phone is called twice in rapid succession, and they'll listen for a modem connection from the monitoring company.
posted by Merdryn at 8:03 AM on July 18, 2005

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