Got broadband but no phone

We have a problem on our phone line where our broadband is working (all be it a bit slower than expected) but our phone is not working.

When the receiver is picked up to make a call there is no dialing tone.

If a call comes in picking up the phone stops the phone ringing but the call does not connect and the "ring" can be heard through the earpiece.

When this happened the first time I reported the problem (to Plusnet who we get our line rental from) and a couple of days later we got a call from an engineer saying it should all be working again (which it was). So the cause must have been external to us.

Now it has done it again.

So I am curious as to what can cause such a line fault that stops the phone working as described, but still allows the broadband to work, as I would have thought a line fault would stop the broadband as well ?

Not necessarily, it depends on the type of fault.
eg. 1 wire disconnected will prevent the phone working but allow the broadband to work at a slower speed.

In reply to a post by jhartridge:

We have a problem on our phone line where our broadband is working (all be it a bit slower than expected) but our phone is not working.

When the receiver is picked up to make a call there is no dialing tone.

If a call comes in picking up the phone stops the phone ringing but the call does not connect and the "ring" can be heard through the earpiece.

When this happened the first time I reported the problem (to Plusnet who we get our line rental from) and a couple of days later we got a call from an engineer saying it should all be working again (which it was). So the cause must have been external to us.

Now it has done it again.

So I am curious as to what can cause such a line fault that stops the phone working as described, but still allows the broadband to work, as I would have thought a line fault would stop the broadband as well ?

Almost certainly one leg is either disconnected, very high resistance or wet and earthing through that.

The nature of the broadband signal is such that it will be received and decoded on a single leg but as the differential with the second leg is missing the received power will be down by at least 6dB and perceived noise can be higher. That will result in a reasonable loss of speed.

Just report it as a voice fault - don't even mention Broadband - it will only confuse.

Thanks for your explanation. I have reported the problem again, but from what you say it could be weather related ? We don't have any flooding round here and our phone line comes up from the ground (not up a pole) but I suppose water damage could be affecting a link in the line somewhere.

Weather related - yes. However, all joints should be sealed against moisture and a some water but flooding of a chamber and duct will often cause ingress into the joint. Having an underground line makes it much more likely.