All you would have to do is disable the wifi on the router GUI so it don't broadcast the wifi signal and tell the Ubiquiti Amplifi HD that the Default Gateway is 192.168.1.1
But you shouldn't need to do any of this at all, if you have either the Thomson THG3000G or a Huawei HHG2500, as they both have a large adequate wifi footprint to send a solid signal around a 4 to 5 bedroom house. I know this because I have tested both these routers and also these routers have Beamforming built in as well.
What you probably have done it not setup the router configuration properly since you have had the router and using the default configuration. You can configure the Vodafone routers to broadcast 3 wifi networks using 2.4Ghz, 5Ghz and a Guest network. What you need to do is go into the router configuration and reconfigure the wifi settings.
To do this do the following:-
Open a web browser, the default static IP address of the router is 192.168.1.1 so type this in the address bar. The default login details are on the bottom or back or the router so login to the router with these.
Once logged in select Expert Mode at the top.
Then select Wi-Fi on the red bar at the top
The toggle the Split Wi-Fi bands (SSID) to on
You will see a list of:-
Main Wi-Fi (2.4 Ghz) - 2.4Ghz network
Main Wi-Fi (5 Ghz) - 5Ghz network
Wi-Fi 2 - (Guest Network) toggle switch to on if it is not already
For the best wireless encryprtion set the Protection Mode to WPA2 (most devices in the last 10 years will be able to connect using this.
The reason for splitting the 2.4Ghz and the 5Ghz wi-fi bands is to make the router perform signal better. What you now need to do is give each one a different name to the Main Wi-Fi (2.4 Ghz), Main Wi-Fi (5 Ghz) and Wi-Fi 2 networks.
On the Wi-Fi 2 network you can also decide if you want to make it just a 2.4Ghz or 5 Ghz network or combine them both. Then after you have done this, scroll down and click Apply at the bottom to update the router configuration. You will now see 3 wireless networks being broadcast.
The next thing you could do to also improve the wireless speed is which under the Wi-Fi options on the red bar at the top. Then select Settings to change the frequencies the wireless networks are broadcast on.
What you want to do is find out what channels your neighbours are using and use and completely difffenent channel from them. There is a good app if you have an Android device on the Google Play Store called Wifi Analyzer this will tell you what frequencies your neighbours wifi is broadcast on.
Because the 2.4Ghz frequency is a very congested band with only 13 channels to pick from, by default the router is set to Auto (this is the channel you want to change by default). The 5Ghz band is not generally congested and has a lot more channels to choose from. Once you find a good 2.4Ghz channel that none of your neighbours are using, select it and click Apply.
With a 2.4 Ghz network it gives a larger wifi range but has less bandwidth, where as 5Ghz has a shorter wifi range but has a lot more faster bandwith and with a Wireless AC device it's even faster.
The other thing I talked about if Beamforming, what that does is when using the Vodafone Broadband app (which is available on Android and IOS). It tracks the device and sends a stronger wireless signal when enabled via the app, as long as the wireless device has beamforming built in, it will tell you within the app if it is.
This is how you should reconfigure and setup not just a Vodafone router but any router from any ISP to get the best performance out of it.
