I wondered if anyone could help me.

I have had BT Infinity 4 installed today and have a download speed of 310mpbs. Despite this, my Amazon Fire TV box is not playing in Ultra HD.

It is showing Ultra HD programmes available to watch under TV and Movies but when I play these, it shows HD 1080p. I have the Display setting set to Auto, which should allow it to show 4k and my TV is compliant on all ports. Anyone know what the issue might be?

It's connected wirelessly by the way.

Thanks!

It may be an issue with your wifi signal make sure your using 5ghz or 5ghz AC if that does not help try using an hard wired connection,you may also want to look into changing your dns to something like opendns/google dns on the fire tv instructions can be found here.

I think your seeing 4k available on the box as its compatible but its does not mean its always available to you

Try using Powerline adapters to get your wired connection if Fire box is a long way from your router. They usually work a treat!!

I just wanted to follow up on this but having discovered no discernible reason why my Amazon Fire box should be not displaying in Ultra HD, I decided to leave a particular programme playing. After several minutes of being shown in HD 1080p, it suddenly switched to Ultra HD.

No idea why it takes so long. It is picking up a wifi signal from BT's new Smart Hub and the download speed is over 300mbps. It is only about 5 metres away from the router too.

Oh well, at least it works. Just surprised it wouldn't switch to Ultra HD instantly.

Your download speed of your BB and what you actually get and what get WiFi is hugely different, I would be surprised if you got more then 40 or 50 megs on your Fire TV by the time it connects. As suggested above try hardwiring it in then you are more likely to get your headline speed.

Not read the thread as some of the info may be out of date now.

I'm thinking of buying this and see them on ebay, would you get the same functionality from a second hand stick? If not who is the most competitive supplier of new?

Functionality will be the same regardless of where you buy it from, you will sign in with your Amazon account and then can download what apps you want and sign into the various different services.