Unfortunately you won't be able to record the NowTV service from your new NowTV box onto your YouView box
The majority of the NowTV shows and movies from your new NowTV box will offer either a catch up or on demand content.
I am guessing you already know that the NowTV App on your YouView box offers on demand NowTV movies only.
I am assuming you have a new NowTV smart box with the inbuilt Freeview channels?
If that's the case then you can still use the YouView box for recording the Freeview channels, where if your YouView box has a RF loop through TV aerial connection, then wire the main TV aerial into the YouView box and then on the aerial out of the YouView box connect to your NowTV smart box.
Make sure in the YouView box menu settings that you switch on RF loop through.
This is the way i have my BT YouView box and NowTV smart box connected in my setup.
If your YouView box doesn't support RF loop through, then use a Y splitter TV cable between the YouView box and Now TV smart box.
If you have any problems wiring the TV aerial between your YouView box and new NowTV smart box, post back here and somebody should be able to assist you further.
Hopefully once you have it all set up (subject to your TV aerial signal strength and you have two HDMI Ports on yourTV) you should be able to watch live Freeview channels on either your YouView box or NowTV smart box.
When you want to record a Freeview channel then use the YouView box EPG and watch back the recordings on your YouView box (like you was doing previously).
Then watching any NowTV content, use your NowTV smart box to watch either the live Now TV channels or watch TV shows on either catch up or boxset (you won't be able to record these mind).
Out of curiosity what is the make and model of your YouView box and are you definitely using a NowTV smart box like the picture below ?
That worked a treat thanks for your help I'm not sure of the model of the youview box. It's a Hunax and I've had it for about 4 years.
@MacSara in that case the model of Youview box you have will likely be a Humax DTR-1000T or Humax DTR-1010T. Yes I know I need to get out more but in my defence, it can sometimes be very helpful to know little snippets of information like that