Every day I have to reboot router because my internet cuts out

[#1]

This has been happening for a while now and to be honest I'm getting fed up with it. Always the same thing: internet cuts out, no matter how long I wait the Internet light on my Plusnet router will remain off or red and only switching the router off and on again will resume my connection.
What is causing this? Faulty router or what?

[#2]

It just happened again, except this time I noticed the phone line also became unavailable.

[#3]

That was me testing your line. 
Our tests aren't showing any obvious issues with the line so it could be the router.
Any chance you can borrow one from a friend or family member?