Phone Line Faults

Here is a brief guide to the most commons problems you will encounter with your home or business phone line. They are listed in order of the most common. But first, here's a basic explanation of how a phone line works.
Your phone line consists of 2 wires. Usually the wires are copper, sometimes aluminium. The one wire is the power (50v approx), the other wire is the earth. They leave the telephone exchange in big cables up to 2000 lines, then via a series of junctions and joints, they arrive at your house in a single cable.
I've used the BT technical term for each fault, plus given an explanation of what they mean.

• Your phone line is completely dead. No dial tone. Probable causes are:

The line is DIS. This simply means the line test is not picking up the capacitance reading of your master socket. Basically, the line is broken through somewhere, so cannot complete the cicuit to give you dial tone.
The line is LOOP. Or in other words, the line has a short cicuit on it. The 2 wires are touching somewhere, so again cannot complete the cicuit.

• Your line is very noisy. May have dial tone, may cut off while using the phone.

Noise faults usually fall into one or more of the 4 categories below:
Battery Contact. This means your line is in contact with another line. Usually caused by water in the system causing the insulation on the wire to break down.