My grandparents have bought a Big Button 200 that "pings" like it's getting a call through every 30 minutes on the dot. The red light comes on very briefly. It pings twice and then stops. When picked up the line isn't dead but no one is on the other end. They have no messages outstanding on the machine. Is there a way to fix this?
Having read through the User Guide, the only suggestion which comes to mind is to check whether an ADSL filter is needed and, if so, that one is in place.
An Openreach Master Socket doesn't need a filter; otherwise one will be required if the line is also configured to carry broadband.
Otherwise it could be there's a fault with the handset or the landline itself. If it's an ordinary socket then dial 17070, select option 2 and the line should be silent. If there is a Master Socket fitted (normally where the line first enters the building from outside) then remove front cover and plug your phone into the designated test socket and dial 17070 and select option 2. Again, the line should be silent. Report any noise as a phone fault to 151.