apps no longer download on wi-fi

[#1]

This is an odd one I can't find a fix for.  We have multiple iphones and ipads on our home network and none of us can download or update any apps from the app store.  As it is all family members it seems the problem must lie at the router.  I do a regular back up of the router settings (the standard Technicolor TG582N) and have tried restoring to a point when the downloads definitely worked but no joy with that.  I've connected my iphone to the wi-fi at work and the downloads from app store work just fine so it's definitely not the devices and the problem lies at the router.  Any ideas how to fix?

Thanks

[#2]

Very odd behaviour...

I can only think of doing a full factory reset of the router or

Can you borrow another router to try?

Richard

[#3]

If budgets allow you could buy a cheap router off ebay?

used and replaces the BT Openreach modem:

http://www.ebay.co.uk/itm/BT-Home-Hub-5-Infinity-Fibre-ADSL-Dual-Band-Wireless-AC-Gigabit-Router-Plu...

New Cheap cable router (needs the Openreach Modem):

http://www.ebay.co.uk/itm/TP-Link-TL-WR841N-4-port-Wireless-Cable-Router-/381038686246?epid=97169862...

New (better than the TG582n & needs the Openreach modem):

http://www.ebay.co.uk/itm/TP-LINK-Archer-C60-Wireless-Cable-Fibre-Router-AC-1350-Dual-b-/12237879936...

Richard