@ColinChambers59
Hey
Yes you can indeed use your existing Deco for Full Fibre connections from Plusnet.
Plusnet will likely install a small white box in your house called an ONT, this is where the fibre comes in from outside and is then coverted to a normal network cable connection. You now have 2 choices here
1. Plug your new/existing Plusnet router WAN PORT into the LAN port on the ONT, then connect your Deco into the one of hte LAN ports on the Plusnet router. This is likely the easiest to setup and wont require any reconfiguring, likely similar to what you have at present
2. Bypass the Plusnet router.. Connect your Deco straight to the ONT LAN port, then you would need to run the internet wizard on your Deco App, choose PPPoE as your internet type and add your plusnet username and password to allow the Deco to connect. The deco is then directly connected and you dont need the Plusnet router at all
IMHO.. option 2 is more setup, but honestly the better option as its not just neater and less hardware, it also avoids double NAT which can be a pain if you have xbox/playstation gamers. I would recommend option 2 personally.