We've had our superhub 3 for years, but recently the range is dropping. I can even go into the room next it with out dropping and losing signal. Do they deteriorate over time? Do I need a new one? We pay (in my opinion) a high premium for this broadband and would expect the range to go beyond the room it is in! I phoned support who offered boosters. But I don't want booster all around the house when all I need is a good router. They sent someone out to look at it but he didn't turn up after I spoke to him over the phone.
It's possible that the Hub could be failing, but more likely is that something has changed in the WiFi environment to affect the signal. For instance, neighbours may have installed WiFi that is interfering with yours.
Have you tried changing the WiFi to different channels? There are also a lot of helpful suggestions at the top of the page.
Make sure the Hub is out in the open and not hidden by any obstructions that can block the signal.
Good suggestions by jpeg1, something else to try is download an app like Wifi Analyzer. Free on Android, works well, and will help you see if there's interference, and it'll give you a measure of signal strength, although you'll need to read Sephiroth's "pink sticky" post about wifi to properly interpret what it is showing you.