Using Omnia with a BTHomeHub as a modem


I’ve been playing with the router on and off on the back of another router, but now I want to have the Omnia standalone. As it doesn’t have a built-in modem, I’d like to use my BTHomeHub3 as a modem, but disable all of its other features. At first attempt, this didn’t work and I’d like to know if anyone else has managed to do the same with this, or another modem/router on ADSL.

On the BTHH3 I’ve disabled wifi/DHCP/DNS but is this right? Anything else that I need to do?