Galaxy Honeywell 2 - Telephone Line Fail

We recently switched from copper internet to full fibre. As a result the copper phone line was cut and since this the alarm (which we inherited with the house and dont use) has gone off weekly quoting a telephone line failure fault. Each time I can silence it by entering the code (we have the Master user code), but I dont appear to be able to get into the engineer section to disable the telephone line functionality.

I have tried the default engineer codes I found quoted on this site and they dont work. I cannot see any way of gaining access beyond the manager user.


Any advice on how to resolve?

TIA,