The procedure is quite common and works for many of us. Make sure the IP address of the Sky router is outside the DHCP address range of your main router, you should be able to ping the address and probably access the Sky routers menu. I have the same SSID and password on both my main router and my access point router but I use different Wifi channels.
Thank you for the reply. Funny enough I was going to ask if this could be the cause as it makes sense.