Are you sure it's your router that's the problem, I was having problems with flickering lights on the router. Borrowed another router from my son in law, turned out not the router, with Plusnet so ended up with openreach coming. Kept saying it's your internal wiring, three engineers said the same each time, FTTC was available in the area so went to that, took a fortnight to get installed, new router from Plusnet and all works well. Strangely it's still using the same internal wiring without problems.