What was found
(CAN) WHILE TAXING WITH ANTI-ICE FOR ICE CONDITIONS BOTH THE LT AND RT WING ANTI-ICE FAIL MESSAGE APPEARED. SUBSEQUENTLY THE LT WING ANTI-ICE FAIL MESSAGE CLEARED BUT THE RT WING ICE REMAINED FAILED. CONTINUOUS LT AND 5 WING AMBER INDICATION. THE FLIGHT CREW RETURNED TO GATE, 28-OCT-2014: IT WAS REPORTED THAT MAINTENANCE REPLACED THE WING ANTI-ICE MODULATING AND SHUTOFF VALVE.