I live with housemates so there was a virgin media router in my place already. I just got another router/ account as sales team told me it would work by connecting the router to the "tv plug".
The router is on but no wifi.
i assume you mean VM hubs - its certainly possible to have 2 accounts at the same address - is that what you mean - and its possible but not normal to run the 2 hubs on the common input
so assuming there are 2 accounts and you have connected the new hub have you rung and activated it - if not you need to do that - if you have what colour is the base light on the hub - if its white post some info
log into hub3 - 192.168.0.1 [or 192.168.100.1 if in modem mode] - DON'T SIGN IN, click - click router status [centre of screen] - and post the downstream and upstream figures - to see those press on the grey buttons/boxes labeled - upstream - downstream
whilst you have problems is the original hub still working