Wireless connection between devices lost

[#1]

Hi,
Sorry this is long winded:-) Any thoughts on the following problem would be appreciated we are really baffled:
Our home network:
Plusnet unlimited broadband ADSL using Thompson TG585 v8 Router 8.2.7.8
2009 MacPro Yosemite 10.10.3 via wireless
2009 iMac Yosemite 10.10.3 via wired ethernet
Canon MG6100 Printer via wireless
iPhone 3gs iOS 6.1.6 via wireless
iPhone 5s iOS 8.1 via wireless
Up to about 10 days ago all the above worked perfectly:
Both Macs, one wireless one wired connected to internet.
Both iPhones connected wirelessly to internet.
Both Macs printed wirelessly to printer.
Both iPhones had various apps (1Password, CDpedia for example) that synced wirelessly to both Macs.
10 days ago we went to print from the Mac Pro, couldn't connect to printer, tried iMac, same, couldn't connect to printer
checked home network in router, printer seen and active.
Connected printer via USB to iMac worked perfectly, switched on printer sharing on iMac able to print from Mac Pro to shared printer on iMac.
Few days later went to sync apps on iPhone 3gs to Mac Pro (did this last successfully about the end of May) apps on iPhone 3gs that were previously able to to sync to equivalent apps on Mac Pro will now not sync. Tried with iMac same no sync.
Checked iPhone 5s, same problem, apps that previously synced with equivalent apps on iMac will now not sync. Tried with Mac Pro same, no sync.
At first I thought the problem could Yosemite, but on the Mac Pro I have a partition with Mountain Lion on, so I booted that and much to my surprise we have exactly the same problem.
To be clear, printing wirelessly and syncing the various apps wirelessly are things we have done numerous times for some years.
Recap the current situation:
Both Macs & both iPhones can connect to the internet via the Thompson TG585
All devices are seen in the Home Network in the router
Both Macs can connect to each via file sharing, both can print to the printer connected via USB on the iMac.
Neither Mac can see the printer wirelessly but the printer is seen active wirelessly in the Home Network in the router.
Neither Mac or iPhone can connect to each other wirelessly.
All devices have been rebooted, we have tried disabling all firewalls.
Any ideas welcome.
Thanks
Steve

[#2]

Since the common factor is the router, could that have started playing-up?  Do you have an alternative router you could try?

[#3]

I keep thinking about the router, however I cannot get my head round what the problem would be, that allows the Mac Pro & iPhones to connect wirelessly to the router and internet with zero issues, yet stop them & printer connecting to each other.
I think we may have a spare thompson that Plusnet sent us ages ago that we never used, just a question of where it is:-)
If not I am really out of touch with what would be a good reasonably priced Mac friendly router to get, any ideas?
adie:quote

[#4]

have you restarted the router?

[#5]

Quote from: dvorak

have you restarted the router?

Now there's a good idea, I thought we had when we first got the printer problem but when I looked at the router up time it had been 45 days, so I just restarted the router and everything is back to normal. I don't understand what happened but thanks, everything now synced and printing wirelessly again:-)