Yesterday afternoon I decided to replace the router in the switch box with my spare one. It's all set up and working, but you may need to tell your devices to connect to it the first time - mine didn't auto-connect at first.
The old router is still in there (unplugged), so we should remove it at some point, but it will be fine for now.
Replacement of router in the switch box
Re: Replacement of router in the switch box
I came in today and the router seems to be working just fine, so hopefully that's the end of our troubles with routers for a while 
Hamish
Re: Replacement of router in the switch box
Router still seems fine, so I think we're good now for the moment on this.
Hamish