My new gigaset AL145 only rings once for incoming calls. Can you advise please? The ringtone starts with a ring then just clicks quietly, so if not heard on first ring the calls will be missed. This is the same on both handsets.

SOURCE: No ring on handset

It may have lost the link to the base unit. Make a note of all the personal details, stored number, etc., then reset the handset. Do this by pressing the spanner button until the display changes, then press and hold the 'R' (delete) button until the handset resets. You'll have to set it up again, but at least it will link.
Spanner then 1 for ringtone, CID for volume.
Spanner then 2 for keypad bleep, 1=off, 2=on.
both cases press spanner to confirm changes.

SOURCE: Siemens 825 Gigaset

I have a Siemens 8825 and it was rebooting too. Clearing the call log fixed the problem.

SOURCE: No ring and appear on my Norstar M7310

I just found out how to do it - it is pretty simple
dial "Feature * 6" from your phone
you can choose the ring type you want by pressing next or 1, 2, 3, 4
then press OK

to adjust the volume
dial "Feature * 80"
then press the volume up or down to the desired volume

SOURCE: uniden 5.8Ghz phone.

You need to reset the main base unit. Unplug the power from the back of the base. While the power is disconnected, press and hold the delete key while reconnecting the power. Wait for a long beep tone. When the display shows 88 or P, press play button one time. If you have a phone without an answering machine, disconnect the power from the back of the base, press and hold find hs button while reconnecting power.

SOURCE: handset won't ring

You need to reset the main base and make sure the ringer volume is turned all the way up. Disconnect the power from the back of the main base, press and hold find hs key while reconnecting power until you hear long beep. Should reset base and handset.